PDA

View Full Version : Here's a riddle about errors when connectiong a 1.2M drive...



nc_mike
May 25th, 2016, 05:16 AM
I've been wrestling with a combination of problems trying to get a 1.4MB, a 1.2M, and 2 CF drives (master and slave) drives all playing nice together. I have a VTG FA-100 FD controller with BIOS (loaded in the Cxxx) range) and the XT-IDE BIOS is loading at D800 - so I don't think I've got a BIOS conflict going on.

The problems occur when I've got the 1.2M 5.25" TEAC FD-55GFR attached as drive B: The drive works, but I get an Internal Stack Overflow - System Halted when it is attached, and I stop getting the error when I remove the 1.2M drive. I've got the standard floppy cable with a twist (I've tried different cables BTW to no avail), with the 4 connectors. Of course I made sure pin 1 on the adapter connector aligns with pin one (red stripe) on cable - the drives don't otherwise work any other way). I've got the 1.44M A: drive connected to the 34 pin connector at the end of the cable and (when connected), connected the 1.2M drive to the 1.2M connector in the middle of the cable. I am fairly certain that I've got the jumpers on the FA-100 set correctly since I can boot from the 1.44M drive and read/write to the 1.2M drive (when it is connected) just fine. The bugger is that dang Internal Stack Overflow - System Halted condition when the 1.2M drive is attached.

Now as more background, I originally had trouble making the FDC co-exist with my older XT-IDE card whose BIOS was fixed at C800. So I had used a trick of bending out a pin to force it to D800 for lack of an on-board jumper. I wasn't getting the Internal Stack Overflow with that combo, but my CF card was getting corrupted intermittently. What I did learn was that when I disconnected the 1.2M drive , that CF corruption stopped (I had previously thought that maybe it was the hanging pin/noise that could have cause the corruption - which might or might not be involved). We'll since then, I replaced the XT-IDE with another one - an XT-IDE Rev 3 that has the address jumper and set it to D800 properly (no hanging pin - yay). Yet, when I attach the 1.2M drive I get the dreaded Internal Stack Overflow - System Halted condition. I am now wondering if the real culprit is the 1.2M 5.25" TEAC FD-55GFR itself and not sure what to do next to isolate the issue - get and try another 1.2M drive? Try attaching another 1.44M drive as B: (not what I really want - I'd prefer to have a 1.2M drive, but could test that just for kicks)?

BTW - as an aside, working with Carlos who built the current XT-IDE adapter, we did try loading the XT-IDE BIOS into the XT-IDE and using a generic 16-bit multi I/O card and the 1.44M drive booted and worked fine (it actually freed up an additional slot as a bonus), but when the 1.2M drive was attached I started getting the Internal Stack Overflow condition as well).

Ideas? Thoughts?

Regards,
Mike

Regards,
Mike

krebizfan
May 25th, 2016, 05:30 AM
I would try it with a 1.44 MB drive just to confirm that it has something to do with the 1.2 MB drive. I doubt it though.

Also, try increasing the stacks value if you are using an OS that can accept that.

Some more information about the system might be helpful.

Edit: See https://support.microsoft.com/en-us/kb/84300

Stone
May 25th, 2016, 05:33 AM
What about 1.2 as A: and 1.44 as B: ?

nc_mike
May 25th, 2016, 05:39 AM
I would try it with a 1.44 MB drive just to confirm that it has something to do with the 1.2 MB drive. I doubt it though.

Also, try increasing the stacks value if you are using an OS that can accept that.

Some more information about the system might be helpful.

Yah, I tried doubling and tripling the number and size of atacks to no avail (went from 8/256, then to 16/256, then to 30/512). Oddly, the internal stack overflow condition would occur when the system was sitting idle for 5, 10, or 15 minutes. I have ample RAM free (about 512KB) even after all drivers are loaded.

Regards,
Mike

nc_mike
May 25th, 2016, 05:40 AM
yah, I could try that swap too - worth testing.

Mike

Malc
May 25th, 2016, 06:11 AM
what HD floppy bios did you use when you had the 16-bit multi I/O card fitted and where did you home the bios ?
What machine are we talking about here ?

Stone
May 25th, 2016, 06:14 AM
If I had to guess I would say.... FrankenMonster. :-)

nc_mike
May 25th, 2016, 07:13 AM
what HD floppy bios did you use when you had the 16-bit multi I/O card fitted and where did you home the bios ?
What machine are we talking about here ?

That's a good question. Carlos flashed the XT-IDE BIOS to add the FD BIOS with the 1.44M fixed as A: and the 1.2M fixed as B: on IRQ 6 of course, but I've since flashed the BIOS at D800 using the general XTP BIOS and removed the FD support, but I still get the Internal Stack Overflow condition even without the FD BIOS support packed in to the XT-IDE BIOS.

I'm doing all of this on my 5160 PC/XT. The machine is fairly packed. here is the full machine spec if you care to see it:

Regards,
Mike

**********************
* System Summary *
**********************

--------------------- Computer ---------------------
Computer Name: IBM XT
Built-in BIOS: IBM, Friday, May 9, 1986
Main Processor: Cyrix 486, 32 MHz
Math Co-Processor: 80387
Video Adapter: VGA, Secondary: None
Mouse Type: Serial Mouse, Version 8.20

--------------------- Disks ---------------------
Hard Disks: 1956M, 1956M
Floppy Disks: 1.44M, 1.2M

--------------------- Memory ---------------------
DOS Memory: 638K
Extended Memory: 18,504K
Expanded Memory: 0K

--------------------- Other Info ---------------------
Bus Type: ISA (PC/AT)
Serial Ports: 2
Parallel Ports: 1
Keyboard Type: 101-Key
Operating System: DOS 7.00



*****************
* CPU Speed *
*****************

This |
Computer +********** 37.7
|
INTEL |
486DX2-66 +************************************ 141.7
|
INTEL |
386DX-33 +********* 35.9
|
INTEL |
286-12 +** 8.9
|
+----+----+----+----+----+----+----+----+----+----+----+---
20 40 60 80 100 120 140 160 180 200 220
Computing Index

Main Processor: Cyrix 486, 32 MHz



*********************
* Video Summary *
*********************

--------------------- Display ---------------------
Video Display Adapter: VGA, Secondary: None
Monitor Type: Analog Color
Current Video Mode: 3 (Color, 80x25)

--------------------- Character ---------------------
Maximum Scan Lines: 400
Character Size: 9 x 16
CGA Cursor Emulation: Enabled

--------------------- Memory ---------------------
Video Memory: 256K or more
Video Segment Address: B800 (hex)
Video Page Size: 4,096 Bytes



********************
* Disk Summary *
********************

Drive Type Size Default Directory
-------------------------------------------------------------
A: 1.44M, 3 1/2" 1.44M
B: 1.2M, 5 1/4" 1.2M
C: Hard Disk 1 1955M C:\
D: Hard Disk 2 1955M D:\
E: 1.44M, 3 1/2" 1.44M
F: Removable 98M F:\
G: CD ROM ? G:\
H: Available
I: Available
J: Available
K: Available
L: Available
M: Available
N: Available
O: Available
P: Available
Q: Available
R: Available
S: Available
T: Available
U: Available
V: Available
W: Available
X: Available
Y: Available
Z: Available


****************************
* Disk Characteristics *
****************************

--------------------- Drive A: ---------------------
Logical Characteristics

Bytes per Sector: 512
Sectors per Cluster: 1
Number of Clusters: 2,847
Number of FAT's: 2
FAT Type: 12-bit
Media Descriptor Byte: F0 Hex
FAT Start Sector: 1 Sectors Occupied 18
Root Dir Start Sector: 19 Sectors Occupied 14
Data Start Sector: 33 Sectors Occupied 2,848

PHYSICAL CHARACTERISTICS

Sides: 2
Tracks: 80
Sectors per Track: 18
Drive Number: 0 Hex
Model: Unknown



--------------------- Drive B: ---------------------
Logical Characteristics

Bytes per Sector: 512
Sectors per Cluster: 1
Number of Clusters: 2,371
Number of FAT's: 2
FAT Type: 12-bit
Media Descriptor Byte: F9 Hex
FAT Start Sector: 1 Sectors Occupied 14
Root Dir Start Sector: 15 Sectors Occupied 14
Data Start Sector: 29 Sectors Occupied 2,372

PHYSICAL CHARACTERISTICS

Sides: 2
Tracks: 80
Sectors per Track: 15
Drive Number: 1 Hex
Model: Unknown



--------------------- Drive C: ---------------------
Logical Characteristics

Bytes per Sector: 512
Sectors per Cluster: 64
Number of Clusters: 61,101
Number of FAT's: 2
FAT Type: 16-bit
Media Descriptor Byte: F8 Hex
FAT Start Sector: 1 Sectors Occupied 478
Root Dir Start Sector: 479 Sectors Occupied 32
Data Start Sector: 511 Sectors Occupied 3,910,528

PHYSICAL CHARACTERISTICS

Sides: 64
Tracks: 970
Sectors per Track: 63
Drive Number: 80 Hex
Model: Unknown



--------------------- Drive D: ---------------------
Logical Characteristics

Bytes per Sector: 512
Sectors per Cluster: 64
Number of Clusters: 61,101
Number of FAT's: 2
FAT Type: 16-bit
Media Descriptor Byte: F8 Hex
FAT Start Sector: 1 Sectors Occupied 478
Root Dir Start Sector: 479 Sectors Occupied 32
Data Start Sector: 511 Sectors Occupied 3,910,528

PHYSICAL CHARACTERISTICS

Sides: 64
Tracks: 970
Sectors per Track: 63
Drive Number: 81 Hex
Model: Unknown



--------------------- Drive E: ---------------------
Logical Characteristics

Bytes per Sector: 512
Sectors per Cluster: 1
Number of Clusters: 2,847
Number of FAT's: 2
FAT Type: 12-bit
Media Descriptor Byte: F0 Hex
FAT Start Sector: 1 Sectors Occupied 18
Root Dir Start Sector: 19 Sectors Occupied 14
Data Start Sector: 33 Sectors Occupied 2,848

PHYSICAL CHARACTERISTICS

Sides: 2
Tracks: 80
Sectors per Track: 18
Drive Number: 20 Hex
Model: Unknown



--------------------- Drive F: ---------------------
Logical Characteristics

Bytes per Sector: 512
Sectors per Cluster: 4
Number of Clusters: 49,046
Number of FAT's: 2
FAT Type: 16-bit
Media Descriptor Byte: F8 Hex
FAT Start Sector: 8 Sectors Occupied 384
Root Dir Start Sector: 392 Sectors Occupied 32
Data Start Sector: 424 Sectors Occupied 196,188

No physical information


--------------------- Drive G: ---------------------
No disk in drive
No physical information




************************
* Partition Tables *
************************

Starting Ending Relative Number of
System Boot Side Track Sector Side Track Sector Sectors Sectors
BIGDOS Yes 1 0 1 63 969 63 63 3,910,977
BIGDOS No 1 0 1 63 969 63 63 3,910,977



**********************
* Memory Summary *
**********************

--------------------- DOS Usage ---------------------
DOS reports 638 K-bytes of memory:
143 K-bytes used by DOS and resident programs
495 K-bytes available for application programs

--------------------- Overall ---------------------
A search for active memory finds:
640 K-bytes main memory (at hex 00000-0A000)
32 K-bytes display memory (at hex 0B800-0C000)
64 K-bytes extra memory (at hex 0E000-0F000)
18,504 K-bytes extended memory (at hex 10000-131200)
0 K-bytes expanded memory

------ ROM BIOS Extensions are located at these segments ------
C000 CE00 D800 DA00


***************************
* Extended Memory (XMS) *
***************************

Total XMS Memory: 4,288K
Allocated: - 0K
--------
Available: = 4,288K

XMS Version: 3.00
Driver Revision: 3.15
Available Handles: 0

High Memory Area: Allocated
A20 Line: Enabled

UMB Server: DOS
Available UMBs: 5K
Largest Free UMB: 5K

Handle Block Size Locks



*************************
* DOS Memory Blocks *
*************************

023C 3,744 INBRDPC Device Driver
0327 816 HIMEM Device Driver
035B 14,400 EMM Device Driver
06E0 1,424 QRAM Device Driver
073A 13,440 BACKPACK Device Driver
0A83 11,680 BPCDDRV Device Driver
0D5E 18,768 SCSIDRVR Device Driver
11F4 8,576 DOS Open Files Table
140D 256 DOS File Control Blocks
141E 512 DOS File Buffers
143F 2,288 DOS Current Directories
14CF 13,104 DOS Stacks
1803 64 DOS DOS System Area
1808 2,368 COMMAND Program
189D 64 Free Memory
18A2 336 COMMAND Environment
18B8 64 Free Memory
18BD 21,632 MSCDEX Program
1E06 352 Free Memory
1E1D 17,056 MOUSE Program
2248 6,032 3C5X9PD Program
23C2 507,840 Free Memory
9FBF 263,184 DOS DOS System Area
E002 7,008 ASPIPPM1 Device Driver
E1BA 23,904 CTSB2 Device Driver
E791 10,528 CTMMSYS Device Driver
EA24 352 Free Memory
EA3B 14,384 SHARE Program
EDBF 2,544 WINPKT Program
EE5F 1,136 DOSKEY Program
EEA7 5,504 Free Memory



**********************
* Device Drivers *
**********************

Address Name Description
-------------------------------------------------------------
00FC:0048 NUL NUL Device
E792:0000 CTMMSYS$ Unrecognized Device
E1BB:0000 CTSOUND0 Unrecognized Device
0D5F:0000 F: Block Device (Data Storage Device)
E003:0000 SCSIMGR$ Unrecognized Device
0A84:0000 BPCDDRV$ Unrecognized Device
074B:0000 E: Block Device (Data Storage Device)
073B:0000 BPDRV$ Unrecognized Device
06E1:0000 EMMQXXX0 Disabled Expanded Memory Manager
035C:0000 EMMXXXX0 Expanded Memory Manager (EMS)
0328:0000 XMSXXXX0 Extended Memory Manager (XMS)
023D:0000 INBRDPC% Unrecognized Device
0072:0003 CON Console Keyboard/Screen
0073:0005 AUX First Serial Port
0074:0007 PRN First Parallel Printer
0075:0009 CLOCK$ System Clock Interface
0076:000B A: - D: DOS Supported Drives
0077:000B COM1 First Serial Port
0078:000D LPT1 First Parallel Printer
0079:000F LPT2 Second Parallel Printer
007B:0008 LPT3 Third Parallel Printer
007C:000A COM2 Second Serial Port
007D:000C COM3 Third Serial Port
007E:000E COM4 Fourth Serial Port





********************
* TSR Programs *
********************

Address Size Owner Hooked Interrupt Vectors
-------------------------------------------------------------------
1809 2,704 COMMAND 22 24 2E
18BE 21,632 MSCDEX
1E1E 17,056 MOUSE 0C 10 33
2249 6,032 3C5X9PD 08 0F
EA3C 14,384 SHARE
EDC0 2,544 WINPKT 60
EE60 1,136 DOSKEY 2F



***************************
* Software Interrupts *
***************************

# Interrupt Name Address Owner

00 Divide by Zero 00FC:108C DOS System Area
01 Single Step 0070:05B0 Unknown
02 Nonmaskable 23D3:26D2
03 Breakpoint 0070:05B0 Unknown
04 Overflow 0070:05B0 Unknown
05 Print Screen F000:FF54 BIOS
06 Invalid Opcode 023D:0603 INBRDPC
07 Reserved F000:FF23 BIOS
08 IRQ0 - System Timer 2249:0B04 3C5X9PD
09 IRQ1 - Keyboard 14D0:0045 DOS
0A IRQ2 - Reserved F000:FF23 BIOS
0B IRQ3 - COM2 F000:FF23 BIOS
0C IRQ4 - COM1 1E1E:02CB MOUSE
0D IRQ5 - Reserved F000:FF23 BIOS
0E IRQ6 - Diskette 14D0:00B7 DOS
0F IRQ7 - Printer 2249:09F8 3C5X9PD
10 Video 1E1E:01D1 MOUSE
11 Equipment Determination F000:F84D BIOS
12 Memory Size Determination F000:F841 BIOS
13 Fixed Disk/Diskette 0A25:0013 BACKPACK
14 Asynchronous Communication F000:E739 BIOS
15 System Services 0328:0131 HIMEM
16 Keyboard F000:E82E BIOS
17 Printer F000:EFD2 BIOS
18 Resident BASIC F600:0000 BIOS
19 Bootstrap Loader 1804:002F DOS System Area
1A Real-Time Clock Services 0070:0648 Unknown
1B Keyboard Break 0070:05AA Unknown
1C User Timer Tick F000:FF49 BIOS
1D Video Parameters F000:F0A4 BIOS
1E Diskette Parameters 0000:0522 Device Driver
1F Video Graphics Characters C000:3F18 BIOS
20 Program Terminate 00FC:1096 DOS System Area
21 General DOS Functions 00FC:10A0 DOS System Area
22 Terminate Address 1809:0293 COMMAND
23 Ctrl+Break Handler Address 23D3:26BA
24 Critical Error Handler 1809:0156 COMMAND
25 Absolute Disk Read 00FC:10AA DOS System Area
26 Absolute Disk Write 00FC:10B4 DOS System Area
27 Terminate and Stay Resident 00FC:10BE DOS System Area
28 DOS Idle 00FC:1156 DOS System Area
29 DOS Internal - FAST PUTCHAR 0070:061E Unknown
2A Microsoft Networks 00FC:1156 DOS System Area
2B Reserved for DOS 00FC:1156 DOS System Area
2C Reserved for DOS 00FC:1156 DOS System Area
2D Reserved for DOS 00FC:1156 DOS System Area
2E DOS - Execute Command 1809:0140 COMMAND
2F Multiplex (Process Interface) EE60:0200 DOSKEY
30 Reserved for DOS FC10:D2EA BACKPACK
31 Reserved for DOS 0000:0000 Unused
32 Reserved for DOS 00FC:1156 DOS System Area
33 Microsoft Mouse Driver 1E1E:005C MOUSE
34 Reserved for DOS 23D3:0833
35 Reserved for DOS 23D3:0833
36 Reserved for DOS 23D3:0833
37 Reserved for DOS 23D3:0833
38 Reserved for DOS 23D3:0833
39 Reserved for DOS 23D3:0833
3A Reserved for DOS 23D3:0833
3B Reserved for DOS 23D3:0833
3C Reserved for DOS 23D3:07FE
3D Reserved for DOS 23D3:082B
3E Reserved for DOS 00FC:1156 DOS System Area
3F Overlay Manager 00FC:1156 DOS System Area
40 Diskette BIOS Revector D800:10D6 BIOS
41 Fixed Disk Parameters 0000:0000 Unused
42 Relocated Video Handler F000:F065 BIOS
43 EGA/VGA User Font Table C000:3B18 BIOS
44 Novell Netware API 0000:0000 Unused
45 Reserved 0000:0000 Unused
46 Fixed Disk Parameters 0000:0000 Unused
47 Reserved 0000:0000 Unused
48 Reserved 0000:0000 Unused
49 Reserved 0000:0000 Unused
4A User Alarm 0000:0000 Unused
4B Reserved 0000:0000 Unused
4C Reserved 0000:0000 Unused
4D Reserved 0000:0000 Unused
4E Reserved 0000:0000 Unused
4F Reserved 0000:0000 Unused
50 Reserved 0000:0000 Unused
51 Reserved 0000:0000 Unused
52 Reserved 0000:0000 Unused
53 Reserved 0000:0000 Unused
54 Reserved 0000:0000 Unused
55 Reserved 0000:0000 Unused
56 Reserved 0000:0000 Unused
57 Reserved 0000:0000 Unused
58 Reserved 0000:0000 Unused
59 Reserved 0000:0000 Unused
5A Reserved 0000:0000 Unused
5B Reserved 0000:0000 Unused
5C Reserved 0000:0000 Unused
5D Reserved 0000:0000 Unused
5E Reserved 0000:0000 Unused
5F Reserved 0000:0000 Unused
60 Reserved for User Programs EDC0:0762 WINPKT
61 Reserved for User Programs 0000:0000 Unused
62 Reserved for User Programs 0000:0000 Unused
63 Reserved for User Programs F000:EC59 BIOS
64 Novell Netware API 0000:0000 Unused
65 Reserved for User Programs 0000:0000 Unused
66 Reserved for User Programs 0000:0000 Unused
67 Expanded Memory 06E1:02CE QRAM
68 Reserved 0000:0000 Unused
69 Reserved 0000:0000 Unused
6A Reserved 0000:0000 Unused
6B Reserved 0000:0000 Unused
6C Reserved 0000:0000 Unused
6D Reserved for VGA C000:25B0 BIOS
6E Reserved 0000:0000 Unused
6F Reserved 0000:0000 Unused
70 IRQ8 - Real-Time Clock 14D0:0052 DOS
71 IRQ9 - Reserved 0D5F:2ABF SCSIDRVR
72 IRQ10 - Reserved 14D0:00CF DOS
73 IRQ11 - Reserved 14D0:00E7 DOS
74 IRQ12 - Reserved 14D0:00FF DOS
75 IRQ13 - Redirect to NMI 0000:0000 Unused
76 IRQ14 - Fixed Disk 14D0:0117 DOS
77 IRQ15 - Reserved 14D0:012F DOS
78 Reserved 0000:0000 Unused
79 Reserved 0000:0000 Unused
7A Novell Netware API 0000:0000 Unused
7B Reserved 0000:0000 Unused
7C Reserved 0000:0000 Unused
7D Reserved 0000:0000 Unused
7E Reserved 0000:0000 Unused
7F Reserved 0000:0000 Unused
80 Reserved for BASIC 0000:0000 Unused
81 Reserved for BASIC 0000:0000 Unused
82 Reserved for BASIC 0000:0000 Unused
83 Reserved for BASIC 0000:0000 Unused
84 Reserved for BASIC 0000:0000 Unused
85 Reserved for BASIC 0000:0000 Unused
86 Reserved for BASIC interpreter 0000:0000 Unused
87 Reserved for BASIC interpreter 0000:0000 Unused
88 Reserved for BASIC interpreter 0000:0000 Unused
89 Reserved for BASIC interpreter 0000:0000 Unused
8A Reserved for BASIC interpreter 0000:0000 Unused
8B Reserved for BASIC interpreter 0000:0000 Unused
8C Reserved for BASIC interpreter 0000:0000 Unused
8D Reserved for BASIC interpreter 0000:0000 Unused
8E Reserved for BASIC interpreter 0000:0000 Unused
8F Reserved for BASIC interpreter 0000:0000 Unused
90 Reserved for BASIC interpreter 0000:0000 Unused
91 Reserved for BASIC interpreter 0000:0000 Unused
92 Reserved for BASIC interpreter 0000:0000 Unused
93 Reserved for BASIC interpreter 0000:0000 Unused
94 Reserved for BASIC interpreter 0000:0000 Unused
95 Reserved for BASIC interpreter 0000:0000 Unused
96 Reserved for BASIC interpreter 0000:0000 Unused
97 Reserved for BASIC interpreter 0000:0000 Unused
98 Reserved for BASIC interpreter 0000:0000 Unused
99 Reserved for BASIC interpreter 0000:0000 Unused
9A Reserved for BASIC interpreter 0000:0000 Unused
9B Reserved for BASIC interpreter 0000:0000 Unused
9C Reserved for BASIC interpreter 0000:0000 Unused
9D Reserved for BASIC interpreter 0000:0000 Unused
9E Reserved for BASIC interpreter 0000:0000 Unused
9F Reserved for BASIC interpreter 0000:0000 Unused
A0 Reserved for BASIC interpreter 0000:0000 Unused
A1 Reserved for BASIC interpreter 0000:0000 Unused
A2 Reserved for BASIC interpreter 0000:0000 Unused
A3 Reserved for BASIC interpreter 0000:0000 Unused
A4 Reserved for BASIC interpreter 0000:0000 Unused
A5 Reserved for BASIC interpreter 0000:0000 Unused
A6 Reserved for BASIC interpreter 0000:0000 Unused
A7 Reserved for BASIC interpreter 0000:0000 Unused
A8 Reserved for BASIC interpreter 0000:0000 Unused
A9 Reserved for BASIC interpreter 0000:0000 Unused
AA Reserved for BASIC interpreter 0000:0000 Unused
AB Reserved for BASIC interpreter 0000:0000 Unused
AC Reserved for BASIC interpreter 0000:0000 Unused
AD Reserved for BASIC interpreter 0000:0000 Unused
AE Reserved for BASIC interpreter F000:E6F2 BIOS
AF Reserved for BASIC interpreter 0000:0000 Unused
B0 Reserved for BASIC interpreter 0000:0000 Unused
B1 Reserved for BASIC interpreter 0000:0000 Unused
B2 Reserved for BASIC interpreter 0000:0000 Unused
B3 Reserved for BASIC interpreter 0000:0000 Unused
B4 Reserved for BASIC interpreter 0000:0000 Unused
B5 Reserved for BASIC interpreter 0000:0000 Unused
B6 Reserved for BASIC interpreter 0000:0000 Unused
B7 Reserved for BASIC interpreter 0000:0000 Unused
B8 Reserved for BASIC interpreter 0000:0000 Unused
B9 Reserved for BASIC interpreter 0000:0000 Unused
BA Reserved for BASIC interpreter 0000:0000 Unused
BB Reserved for BASIC interpreter 0000:0000 Unused
BC Reserved for BASIC interpreter 0000:0000 Unused
BD Reserved for BASIC interpreter 0000:0000 Unused
BE Reserved for BASIC interpreter 0000:0000 Unused
BF Reserved for BASIC interpreter 0000:0000 Unused
C0 Reserved for BASIC interpreter 0000:0000 Unused
C1 Reserved for BASIC interpreter 0000:0000 Unused
C2 Reserved for BASIC interpreter 0000:0000 Unused
C3 Reserved for BASIC interpreter 0000:0000 Unused
C4 Reserved for BASIC interpreter 0000:0000 Unused
C5 Reserved for BASIC interpreter 0000:0000 Unused
C6 Reserved for BASIC interpreter 0000:0000 Unused
C7 Reserved for BASIC interpreter 0000:0000 Unused
C8 Reserved for BASIC interpreter 0000:0000 Unused
C9 Reserved for BASIC interpreter 0000:0000 Unused
CA Reserved for BASIC interpreter 0000:0000 Unused
CB Reserved for BASIC interpreter 0000:0000 Unused
CC Reserved for BASIC interpreter 0000:0000 Unused
CD Reserved for BASIC interpreter 0000:0000 Unused
CE Reserved for BASIC interpreter 0000:0000 Unused
CF Reserved for BASIC interpreter 0000:0000 Unused
D0 Reserved for BASIC interpreter 0000:0000 Unused
D1 Reserved for BASIC interpreter 0000:0000 Unused
D2 Reserved for BASIC interpreter 0000:0000 Unused
D3 Reserved for BASIC interpreter 0000:0000 Unused
D4 Reserved for BASIC interpreter 0000:0000 Unused
D5 Reserved for BASIC interpreter 0000:0000 Unused
D6 Reserved for BASIC interpreter 0000:0000 Unused
D7 Reserved for BASIC interpreter 0000:0000 Unused
D8 Reserved for BASIC interpreter 0000:0000 Unused
D9 Reserved for BASIC interpreter 0000:0000 Unused
DA Reserved for BASIC interpreter 0000:0000 Unused
DB Reserved for BASIC interpreter 0000:0000 Unused
DC Reserved for BASIC interpreter 0000:0000 Unused
DD Reserved for BASIC interpreter 0000:0000 Unused
DE Reserved for BASIC interpreter 0000:0000 Unused
DF Reserved for BASIC interpreter 0000:0000 Unused
E0 Reserved for BASIC interpreter 0000:0000 Unused
E1 Reserved for BASIC interpreter 0000:0000 Unused
E2 Reserved for BASIC interpreter 0000:0000 Unused
E3 Reserved for BASIC interpreter 0000:0000 Unused
E4 Reserved for BASIC interpreter 0000:0000 Unused
E5 Reserved for BASIC interpreter 0000:0000 Unused
E6 Reserved for BASIC interpreter 0001:0000 Device Driver
E7 Reserved for BASIC interpreter 552E:0001
E8 Reserved for BASIC interpreter 552E:552E
E9 Reserved for BASIC interpreter 089E:3AF6 BPCDDRV
EA Reserved for BASIC interpreter 729B:0202
EB Reserved for BASIC interpreter 72FA:71EB Unknown
EC Reserved for BASIC interpreter 0E36:0E36 SCSIDRVR
ED Reserved for BASIC interpreter 0900:0800 BACKPACK
EE Reserved for BASIC interpreter 0E0A:2E36 SCSIDRVR
EF Reserved for BASIC interpreter 0002:0007 Device Driver
F0 Reserved for BASIC interpreter 0A00:DA00 DOS
F1 Reserved for User Programs 0E0A:2E36 SCSIDRVR
F2 Reserved for User Programs BF06:0007 BIOS
F3 Reserved for User Programs CE00:08FD BIOS
F4 Reserved for User Programs CE00:08FD BIOS
F5 Reserved for User Programs 03CE:7207 BPCDDRV
F6 Reserved for User Programs 0000:0720 Device Driver
F7 Reserved for User Programs 0000:1FA2 DOS System Area
F8 Reserved for User Programs 0000:0000 Unused
F9 Reserved for User Programs 27EB:19F6
FA Reserved for User Programs 0200:0003 DOS System Area
FB Reserved for User Programs 0000:0000 Unused
FC Reserved for User Programs 003E:0000 Device Driver
FD Reserved for User Programs 7C00:0080 Unknown
FE Reserved for User Programs E696:0000 CTSB2
FF Reserved for User Programs 7206:F000 Unknown


***********************************
* CONFIG.SYS file from drive C: *
***********************************

DEVICE=INBRDPC.SYS NOCACHE NODIAGS NOPAUSE
DEVICE=C:\DOS\HIMEM.SYS
DOS=HIGH,UMB
BUFFERS=30
FILES=150
LASTDRIVE=Z
REM STACKS=9,256
STACKS=24,512
DEVICE=EMM.SYS PC 258 EP=C800-DFFF ND NP
DEVICE=C:\QRAM\QRAM.SYS R:0 FL=0
DEVICE=C:\backpack.sys
DEVICE=bpcddrv.sys /d:bpcddrv$
DEVICEHIGH=C:\IOMEGA\ASPIPPM1.SYS FILE=NIBBLE.ILM SPEED=10 Quiet
DEVICEHIGH=C:\IOMEGA\ASPIPPM2.SYS FILE=NIBBLE2.ILM SPEED=10 Quiet
DEVICEHIGH=C:\IOMEGA\ASPIIDE.SYS Scan Info Quiet
DEVICE=C:\IOMEGA\SCSICFG.EXE /V
DEVICEHIGH=C:\IOMEGA\SCSIDRVR.SYS
DEVICEHIGH=C:\SB\DRV\CTSB2.SYS /UNIT=0 /BLASTER=A:220 I:5 D:1
DEVICEHIGH=C:\SB\DRV\CTMMSYS.SYS
REM DEVICE=C:\DOS\RAMDRIVE.SYS 1024 /e
REM DEVICE=VANSI.SYS
DEVICEHIGH=C:\DOS\SETVER.EXE
REM DEVICE=C:\WINDOWS\SMARTDRV.EXE /DOUBLE_BUFFER
REM DEVICE=C:\WINDOWS\IFSHLP.SYS



*************************************
* AUTOEXEC.BAT file from drive C: *
*************************************

C:\CACHE\cx486 q C:\CACHE\cx486.cfg
C:\CACHE\fastio.exe
@ECHO OFF
SET BLASTER=A220 I5 D1 T3
SET SOUND=C:\SB
SET MIDI=SYNTH:1 MAP:E
REM C:\WINDOWS\SMARTDRV.EXE /L /X 2048 128
SET READIBM=C:\READIBM\READIBM.PRO
IF EXIST BPCDDRV$ MSCDEX /D:BPCDDRV$
PATH=C:\DOS;C:\TRUMPET;C:\WINDOWS;C:\WINWORD;C:\3C 509;C:\MTCP
PATH %path%;C:\FL;C:\SYSINFO7;C:\WP51\;C:\123R24;C:\KED IT
PATH %path%;C:\ALDUS;C:\PM4;C:\AOL;C:\READIBM;C:\QMODEM ;C:\ACRODOS
PATH %path%;C:\TPW;C:\TPW\UTILS;C:\TP;C:\TPUTILS;MSIE50
SET TEMP=C:\TEMP
SET MTCPCFG=c:\packet\tcp.cfg
@SET SCSI_DRIVER = C:\IOMEGA
@SET SCSI_UTILITY = C:\IOMEGA
MOUSE
LH C:\DOS\SHARE.EXE /l:500 /f:5100
REM LH C:\DOS\SHARE.EXE /F:5120 /L:2000
C:\QBOOKS\BIZMIND C:\QBOOKS /p
VER
3c5x9pd.com 0x60
LH WINPKT 0x60
LH DOSKEY.COM
DHCP

fatwizard
May 25th, 2016, 07:25 AM
Maybe the 1.2 drive is buggered somehow. Have you tried a different drive?

nc_mike
May 25th, 2016, 07:33 AM
Maybe the 1.2 drive is buggered somehow. Have you tried a different drive?

That is my suspicion too - although I don't know which other 1.2M model(s) would be good to try. I ought to also try the suggestions of flopping the drive order and trying a 1.44M in place of the 1.2M, but at the end of the day, it might just be that 1.2M drive.

Regards,
Mike

krebizfan
May 25th, 2016, 07:34 AM
Aaargh, too complex. Too many variables. Simplify that system to even have a chance of catching what is conflicting.

I have read (on Usenet) that some Cyrix 486 systems had issues with certain floppy controllers. Not enough information there to provide a clue as to a fix.

Could be related to 1.2MB drive; could be related to having 2 floppy drives; could be related to something else. Testing with both floppy positions having known working 1.44MB drives would at least confirm whether the problem is really related to the floppy subsystem or if other components are the likely cause.

Chuck(G)
May 25th, 2016, 07:45 AM
I doubt that it's the drive. Start with your FDC BIOS (since this is a PC XT, it's got to have one. Disable it--it won't boot high-density disks, but you'd like to see it get through a boot.

As someone else suggested, it's worthwhile substituting (another) 1.44M for the 1.2M, leaving everything else the same. That should show that the problem is probably not with the drive.

My suspicion is that there's a conflict between all those drivers and low RAM (BIOS RAM) use.

Stone
May 25th, 2016, 07:52 AM
If you find the drive order is the culprit (and you want to or need to easily boot from B: for whatever the reason) there is a neat little program, 'BootB', that produces a boot floppy for drive A: that in turn, when run, proceeds to boot the machine from B: automatically. With this you can boot from either floppy drive without having to change any hardware cables or BIOS settings in the case of some ATs that allow swapping of floppy drives that way. I believe this program was developed to allow those programs (primarily games) with boot loaders to be run in a machine that doesn't have the correct floppy drive configured as A:. Of course, you can use it for whatever purpose you desire. :-)

nc_mike
May 25th, 2016, 08:15 AM
I doubt that it's the drive. Start with your FDC BIOS (since this is a PC XT, it's got to have one. Disable it--it won't boot high-density disks, but you'd like to see it get through a boot.

As someone else suggested, it's worthwhile substituting (another) 1.44M for the 1.2M, leaving everything else the same. That should show that the problem is probably not with the drive.

My suspicion is that there's a conflict between all those drivers and low RAM (BIOS RAM) use.

Yah, good point...I could remove drivers loading high and add them back in individually until I hit the condition if that's what it is. The only curious detail is it only happens when the 1.2M drive is attached and the condition is gone if I detach the 1.2M - that much I can be certain. I'll try this systematically - first I'll try a 1.44M in place of the 1.2M and see if I get the overflow, then swap the order and then if that doesn't reveal anything put all my drivers low, attach the 1.2M, then see if the condition occurs when they are all low or if the conditions rears its head with putting them back up high one by one.

nc_mike
May 25th, 2016, 09:11 AM
Another variable ...I just pulled the 1.2M drive and attaching a pic of its jumpers. I don't know if the jumper settings might have any involvement in the issue, but attaching it anyway in case someone notices something odd. The drive is a TEAC 1.2MB floppy drive FD-55GFR drive and here are the jumper settings someone has posted. I just don't know which one(s) might be involved. https://groups.google.com/forum/#!ms...c/ogjLfUcqYRAJ and http://deramp.com/downloads/floppy_d...B%20floppy.pdf

Regards
Mike3134731348

krebizfan
May 25th, 2016, 09:46 AM
Everything looks right as far as I can tell.

Incorrect jumper settings might result in diskettes that can't be read in a different system, not crashing the system. The two items that might cause weird data loss issues could be termination or excessive power draw.

Do you have a more conventional AT style system to test just the drive?

nc_mike
May 25th, 2016, 11:21 AM
Everything looks right as far as I can tell.

Incorrect jumper settings might result in diskettes that can't be read in a different system, not crashing the system. The two items that might cause weird data loss issues could be termination or excessive power draw.

Do you have a more conventional AT style system to test just the drive?

Good to know - it looked OK to me too.

OK, on to test with another 1.44M drive....

Regards,
Mike

nc_mike
May 25th, 2016, 01:20 PM
Latest update: I put a 1.44M drive as B: in place of the 1.2M drive. The system boots fine, bootable off of the floppy or CF. I can read/write/format 1.44M disks in both drives, and no incidents Internal Stack Overflow-System Halted. Interesting, eh" If it was a BIOS area memory conflict I think the 1.44M floppy B; would exhibit the same symptoms. This is yet another data point that suggests the problem to actually be the 5.25" 1.2M drive itself, yes?

Regards,
Mike

Stone
May 25th, 2016, 01:36 PM
Not until you reverse the drive order. :-)

krebizfan
May 25th, 2016, 01:49 PM
It is a strange set of symptoms. Never heard of a drive failing like that. I think testing on more typical hardware would confirm the drive's status. If the drive works with other hardware, a different flaw needs to be discovered since the replacement 5.25" drive would also fail.

Chuck(G)
May 25th, 2016, 01:56 PM
Well, here's the problem. Legacy floppy drives are basically very simple brain-dead devices--and the difference between a 1.2MB 5.25" drive and a 3.5" drive is very small. (basically, the 3.5" handles media detection; the 5.25" needs to be told (via pin 2) what it's dealing with). 3.5" drives usually spin at 300 RPM; 5.25" drives usually spin at 360 (although either can be changed via configuration jumpers). Both have 2 sides and 80 cylinders.

The signals that are transmitted from the drive to the host are also limited: Track 0, Write protected, Read Data, Index and Disk Changed.

(In all of this, I'm assuming that there's no disk already in the drive). So, if there's no floppy in the drive, you can leave out read data and index.

To me this boils down to only a couple of possibilities. (1) Your drive is jumpered so that it's sending out the wrong signal. You should have the following options jumpered: D1 (second drive select) and DC (disk change on pin 34). No others should be jumpered.

(2) The drive is bad. Try it on a different machine.

Stone
May 25th, 2016, 01:58 PM
...If the drive works with other hardware, a different flaw needs to be discovered since the replacement 5.25" drive would also fail.Not necessarily. Not if it didn't. :-)

nc_mike
May 25th, 2016, 02:22 PM
Well, here's the problem. Legacy floppy drives are basically very simple brain-dead devices--and the difference between a 1.2MB 5.25" drive and a 3.5" drive is very small. (basically, the 3.5" handles media detection; the 5.25" needs to be told (via pin 2) what it's dealing with). 3.5" drives usually spin at 300 RPM; 5.25" drives usually spin at 360 (although either can be changed via configuration jumpers). Both have 2 sides and 80 cylinders.

The signals that are transmitted from the drive to the host are also limited: Track 0, Write protected, Read Data, Index and Disk Changed.

(In all of this, I'm assuming that there's no disk already in the drive). So, if there's no floppy in the drive, you can leave out read data and index.

To me this boils down to only a couple of possibilities. (1) Your drive is jumpered so that it's sending out the wrong signal. You should have the following options jumpered: D1 (second drive select) and DC (disk change on pin 34). No others should be jumpered.

(2) The drive is bad. Try it on a different machine.

it looks like the two jumpers are set to D1 and DC (I attached a picture in a recent post earlier in the thread. I don't have another machine to test it in (I hope to add an 5170/AT to my collection next, so I can keep the drive around in case it works in that machine, but I have no other way to test it otherwise.

Regards,
Mike

nc_mike
May 25th, 2016, 02:23 PM
True. I haven't done that test yet - up next...

Mike

hargle
May 26th, 2016, 06:40 AM
Oddly, the internal stack overflow condition would occur when the system was sitting idle for 5, 10, or 15 minutes.

Feels longshot-ish, but do you happen to have a virus on your machine and there is a file only on a 1.2 floppy that the virus is targeting and then crashing with the stack overflow?

nc_mike
May 26th, 2016, 02:32 PM
Feels longshot-ish, but do you happen to have a virus on your machine and there is a file only on a 1.2 floppy that the virus is targeting and then crashing with the stack overflow?

I spoke too soon. It took a lot longer after I replaced the 1.2M drive with a 1.44M drive, but I finally got the dreaded Infernal Stack Overflow-System Halted again - and that was with 2 1.44M drives. Grrrrr. This morning I swapped the order the 1.44M drives (Made A: the B: drive and visa versa), and its gone all day without an Infernal Stack Overflow occurrence - at least not yet. That is making me wonder if the1.44MB drive is the issue (or reconnecting its cable). That 1.44M A: drive has never changed in the equation before now or throughout many variations I've done. We'll see, if I don't get another failure by tomorrow (the failures usually occur when the system is idle anywhere from 15 min to 3 hours up until now), then just maybe.....


Regards,
Mike

Chuck(G)
May 26th, 2016, 03:08 PM
To me, it sounds like you might have a driver or program sitting in the background chewing up your memory and CPU cycles.

The only way to tell for certain is by process of elimination. Remove all device drivers and resident programs and then add them back one at a time. See if that narrows things down a bit.

Stone
May 26th, 2016, 03:21 PM
Don't forget... when you're dealing with a FrankenMonster there's always the possibility of the introduction of hitherto undocumented demons.

nc_mike
May 26th, 2016, 03:48 PM
To me, it sounds like you might have a driver or program sitting in the background chewing up your memory and CPU cycles.

The only way to tell for certain is by process of elimination. Remove all device drivers and resident programs and then add them back one at a time. See if that narrows things down a bit.

That remains a possibility. Before I go through that hell I want to see if the error resurfaces with the swapping of the 1.44 drives or reseating of the cable. If that doesn't hold (and so far it has), then I'll surrender and start the painstaking process of driver elimination, starting with those loaded high.

My wife says I live for these challenges, but I could have done without one of my 3TB drives in a Quad 12GB RAID10 array and my 4TB Seagate external backup drive all going belly-up in the same week :-)

Chuck(G)
May 26th, 2016, 05:02 PM
Thanks for that--I've long debated as to whether or not the >2GB consumer hard drives are worth it. So far, I've stuck with <1GB drives and haven't had a failure in years. I tend to think that 500GB was a sweet spot in drive design.

I'm sure that others will disagree.

Al Kossow
May 26th, 2016, 05:30 PM
Thanks for that--I've long debated as to whether or not the >2GB consumer hard drives are worth it. So far, I've stuck with <1GB drives and haven't had a failure in years. I tend to think that 500GB was a sweet spot in drive design.

I'm sure that others will disagree.

1TB was when they went to vertical recording and much more aggressive error correction.

bobba84
May 26th, 2016, 07:37 PM
This article (https://www.backblaze.com/blog/hard-drive-reliability-stats-for-q2-2015/) may be of interest

There seem to be some very bad size / brand combinations to avoid. It seems Seagate aren't what they used to be.

Chuck(G)
May 26th, 2016, 08:26 PM
This article (https://www.backblaze.com/blog/hard-drive-reliability-stats-for-q2-2015/) may be of interest

There seem to be some very bad size / brand combinations to avoid. It seems Seagate aren't what they used to be.

Reading through the comments, I don't know what to think! :huh:

bobba84
May 26th, 2016, 10:46 PM
Reading through the comments, I don't know what to think! :huh:

I guess they show the difference between statistics and opinions!

Tor
May 27th, 2016, 01:05 AM
I only feel reasonably safe when my _backups_ are triple-copied. My USB disks (mostly 3TB ones) are LaCie, i.e. Seagate, and no trouble so far, but they don't run all the time obviously. The thing is, they're so cheap around here (Japan) that I can buy lots of them, so if I just keep up my rsync schedule to keep my backups triplicated I should be ok even if one or two of them fail at the same time. The only issue is that the comp I have here only has USB2 and that slows down the backup quite a lot. Particularly when copying between disks. So maybe I should look for the absolutely cheapest otherwise useless mini-notebook w/USB3.0, install Debian or Ubuntu, and use it as a backup support device. Copying over the network from my real notebook would also be faster than it is now.

nc_mike
May 27th, 2016, 02:48 AM
I only feel reasonably safe when my _backups_ are triple-copied. My USB disks (mostly 3TB ones) are LaCie, i.e. Seagate, and no trouble so far, but they don't run all the time obviously. The thing is, they're so cheap around here (Japan) that I can buy lots of them, so if I just keep up my rsync schedule to keep my backups triplicated I should be ok even if one or two of them fail at the same time. The only issue is that the comp I have here only has USB2 and that slows down the backup quite a lot. Particularly when copying between disks. So maybe I should look for the absolutely cheapest otherwise useless mini-notebook w/USB3.0, install Debian or Ubuntu, and use it as a backup support device. Copying over the network from my real notebook would also be faster than it is now.

I have to say I've had several HDDs fail over the years, and I've never lost data, not once. It sounds more complex and expensive, but having a RAID 10, SATA3 setup with four 3TB drives has made it easy to prevent disaster. When one goes the system tells me and I simply remove the failing drive that the other 3 automatically rebuild. I could even lose two drives, but haven't. RAID 10 provides the speed of RAID 0 with the protection of RAID 1, but even better. The cost is that with RAID 10 the total storage of the drives is halved - so a 12TB four-drive array yields 6TB in usable storage, but its worth it. That size array is overkill for some - about $400, but it can be done for a fraction of that with smaller drives at a fraction of the cost - I need a lot of storage for video and imaging work. But, even with all of that, I still have external backup both on-prem and cloud for the most critical data, which is probably overkill, but when you cannot afford to lose data...

....but I digress. I have not had the Internal Buffer Overflow-System Halted condition re-appear. It should have by now, but still watching and hoping the re-cabling or switching the order of the drives was the cause.

Regards,
Mike

Caluser2000
May 27th, 2016, 06:12 PM
....but I digress. I have not had the Internal Buffer Overflow-System Halted condition re-appear. It should have by now, but still watching and hoping the re-cabling or switching the order of the drives was the cause.

Regards,
MikeIs this with two 1.44 drives still? Having a spare 1.2meg drive handy would be a good idea all the same.

nc_mike
May 28th, 2016, 02:05 AM
Is this with two 1.44 drives still? Having a spare 1.2meg drive handy would be a good idea all the same.

Yes, this is with two 1.44MB drives. Its working great now and I might leave it that way. I also have acquired a new PC clone with both a 1.44MB and 1.2M drive. On the rare occasion I need to copy 5.25" disks I'll use that machine to do it, and I'll probably add and XT-IDE+CF to that machine so that I can directly install a rare app that will only install from a 5.25" install disk. I do have an additional spare 1.2MB drive now and I might try plugging it up to the 5160 now that I've swapped the order of the 1.44MB drives and it began to work without the system halting - if for no other reason than to satisfy my curiosity if swapping the two drives was the fix (that was suggested earlier and I didn't get around to trying it before I did the swap with another 1.44MB drive.) If that works then maybe I'll leave the 1.2MB in there after that. It's all so time consuming, and the darn job that yields a paycheck remains my biggest barrier.

I think this swapping of the pair of 1.44MB drives and it working has ruled out a drive/memory conflict cause - at least when using the VTG FA-100 floppy controller with its own FDD BIOS. This modified 5160 system is one of those overly-packed ones - there so much in there that diagnosing issues like this gets to be like a Rubick's cube - and I'm at the point where this particular system is pretty maxed out hardware wide and I'm ready to just load more DOS and Win applications to the long list already installed, including upgrading to Windows Pen OS extension with the WinWriter Pad, and maybe OS/2 2.x for Windows 3.1 just to see if the system can handle it (on a different CF card of course). Then its will be time to get back to working on other a bunch of other vintage systems in the collection. Like so many others, it started out with just one vintage system and it just grows...

Regards,
Mike

bear
May 28th, 2016, 10:59 AM
One thing occurs to me... what's the PSU rated? With all the stuff you've crammed in, if you're right at the limit of the PSU's design envelope, or more that the added 5.25" floppy puts you right at it and the second 3.5" puts you just ever so slightly under it... you may find that the system behaves peculiarly, and possibly even in this kind of way.

nc_mike
May 28th, 2016, 11:19 AM
One thing occurs to me... what's the PSU rated? With all the stuff you've crammed in, if you're right at the limit of the PSU's design envelope, or more that the added 5.25" floppy puts you right at it and the second 3.5" puts you just ever so slightly under it... you may find that the system behaves peculiarly, and possibly even in this kind of way.

Point taken - I had been considering the same thing; It's a 165W PSU. I was looking at a 200W Astec AA14220 PSU recently just for that very reason, but although it will work in a 5160 I understand it isn't an exact fit/fax doesn't line up. I also have a small fan I installed inside the front of the chassis to move some air which pulls a few more watts; I had it in there because I upgraded the 386 InBoard to a 486 Cyrix 25/50 and added it just for good measure as I like to keep the XT case closed. Not sure how best to test if I'm hitting the max power pull.

Regards,
Mike

bear
May 28th, 2016, 12:02 PM
For the purposes of experimentally testing the theory, does it matter that it isn't an exact fit?

Stone
May 28th, 2016, 01:22 PM
Not sure how best to test if I'm hitting the max power pull.Plug in a FHHD. If the machine croaks -- the PSU is maxed out. If it's already close even a HHHD should shut it down.

nc_mike
May 29th, 2016, 03:59 AM
Maybe I can use some sort of voltage tester to really find out; I think I've seen a few that do that. I am not opposed to dropping in a more powerful, non standard PSU; I just prefer the plugs and switch align with the existing case and it be securely attached, but according to the one person that answered my other post about the Astex 200W PSU, it does not of those. I *think* I have the standard PC/XT PSU @ 130W, but not 100% certain. My PSU's fan inside the case is mounted at an angle, which makes me suspicious that it might just be an XT-286 157W PSU. I would really like a higher wattage one that fits in the case correctly. If the issue ever rears its ugly head again or I get more time to test for the original cause of the error, then I might try a few other things like pull out the extra internal fan and one of the non-essential adapters like the 8MB Intel above Board and SB adapter to lighten the load when I put a 5.25" disk in there.

Regards,
Mike

Regards,
Mike