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glitch
March 29th, 2011, 05:40 PM
Does anyone have a monitor that works with the Vector Graphic ZCB, using the built-in serial port as the console? I'm working on repairing a ZCB, and I'm pretty sure it's working, but that the PROM in the PROM 0 socket isn't the right one.

I've got the ZCB's power-on-jump function disabled, and have a Dajen SCI loading its monitor from there. I can dump the contents of the PROM 0 slot at E000. I can also initialize the 8251 UART and push characters out from the SCI monitor. So I'm pretty confident the ZCB is up and running.

If you either enable power-on-jump or use the SCI monitor to jump into E000, the ROM currently in the board writes some data to ports 02 and 03, which aren't the correct ports for the ZCB's UART -- it lives on ports 04 and 05. As such, I'm pretty sure it's the wrong monitor PROM. Does anyone have an image of either a prebuilt-compatible monitor, or one that can be altered to talk to an 8251 on ports 04 and 05?

MikeS
March 29th, 2011, 06:55 PM
Does anyone have a monitor that works with the Vector Graphic ZCB, using the built-in serial port as the console? I'm working on repairing a ZCB, and I'm pretty sure it's working, but that the PROM in the PROM 0 socket isn't the right one.

I've got the ZCB's power-on-jump function disabled, and have a Dajen SCI loading its monitor from there. I can dump the contents of the PROM 0 slot at E000. I can also initialize the 8251 UART and push characters out from the SCI monitor. So I'm pretty confident the ZCB is up and running.

If you either enable power-on-jump or use the SCI monitor to jump into E000, the ROM currently in the board writes some data to ports 02 and 03, which aren't the correct ports for the ZCB's UART -- it lives on ports 04 and 05. As such, I'm pretty sure it's the wrong monitor PROM. Does anyone have an image of either a prebuilt-compatible monitor, or one that can be altered to talk to an 8251 on ports 04 and 05?I might be able to help you:

2 x 2708 or?
Version number ?
Port jumpers set correctly?
Which disk controller if any (Tandon/Micropolis ?)
Any other I/O cards on the bus (e.g. Bitstreamer?)

PM

@ Bill D: I haven't forgotten; are you still interested?

MikeS
March 30th, 2011, 08:02 AM
Don't know why I suggested PM; probably better in the forum in case someone has more info than I.

Don't know how much I can help you; is there any version info on or in that 2716? There were several different monitors (and different revs), depending on whether you were using an RS-232 console or the VG Flashwriter and whether the FDC was Tandon or Micropolis. And of course since it's an SBC it could have a completely custom program in there.

Mine is V4.0C which is for RS-232 console and Micropolis FDC; unfortunately it's on 2 x 2708 and I'd have to do some fiddling to read them on my programmer or in the VG itself.

It's been a loooong time since I played with this, but IIRC the RS-232 port is set to 0/1 or 4/5 depending on whether the console is on the ZCB or the Bitstreamer, and looking at the 4.0 monitor source even the Flashwriter console uses 0/1; don't know why you'd get data on 2/3 unless it's an echo of 0/1.

I think the factory default for the RS-232 connector on the ZCB is 04/05 (E1-E4) instead of 00/01 (E1-E3).

But as I say, its been a long time so take my ramblings with a grain or two of NaCl.

MikeS
March 30th, 2011, 02:28 PM
M: Are/were there jumpers for the port selects or does it still have the default traces? If it worked with the defaults then this is irrelevant, but if there are jumpers why not try setting the RS-232 base port to 00 instead of 04?


G: There are jumpers, but it just sets the higher bits of the address, i.e. you can have it at 04/05, 14/15...f4/f5, but you can't really move the low nybble around.

I don't think that's quite the way it works; all the I/O ports must be within one of eight groups of 32 and the base address of the desired group (even numbers only, i.e. 00, 20, 40, etc.) is selected by the 'G' jumper block.

Within the selected group the base addresses of the serial port and the three parallel ports (blocks of four, i.e. 00, 04, 08, etc.) are selected by two jumpers in the 'E' block, one for the serial port and the other for the parallel ports. The upper two addresses of each 4-address block are merely echoes of the lower two when it's a serial port.

To place the RS-232 port at 00-01, jumper G 2-7, 4-8 and 6-9 (Group 00, the default) and E 1-3 (default is 1-4 and 2-5). Note that the defaults are pcb traces, not jumpers.

At least that's the way it is on my ZCB (REV 1). Do you have a manual to look at?

glitch
March 30th, 2011, 03:47 PM
So I took Mike's advice and read through the I/O port strapping again. Turns out G doesn't do what I need, but E does. Well, E will allow you to set on 4-byte address boundaries; that is, 00 and 01, 04 and 05, 08 and 09, et c. Except the ZCB mirrors the ports for the 8251, so strapping for 00 and 01 also places it at 02 and 03, our magic numbers from before. I changed the strapping, booted, and jumped into E000 from the SCI monitor:


NORTHSTAR SYSTEM MONITOR V1.5
.
.D E000 E100
E000: C3 1E E0 C3 2D E0 C3 F0 - E6 C3 06 E7 C3 32 E7 C3 ....-........2..
E010: 41 E7 C3 46 E7 C3 AC E1 - C3 3A E1 C3 50 E7 31 32 A..F.....:..P.12
E020: FF CD D2 E6 CD 46 E7 21 - 6E E7 CD 32 E7 FB 31 32 .....F.!n..2..12
E030: FF CD 46 E7 3E 00 32 00 - FF 32 01 FF 3E 2E CD 06 ..F.>.2..2..>...
E040: E7 CD F0 E6 FE 0D CA 2D - E0 11 2D E0 D5 FE 42 CA .......-..-...B.
E050: 86 E0 FE 45 CA 8D E0 FE - 44 CA C1 E0 FE 53 CA 2D ...E....D....S.-
E060: E1 FE 4C CA AC E1 FE 4D - CA 2C E2 FE 46 CA 60 E2 ..L....M.,..F.`.
E070: FE 55 CA 95 E2 FE 47 CA - 7B E0 C9 D1 CD 41 E7 CD .U....G.{....A..
E080: 8D E6 CD 46 E7 E9 D1 CD - 46 E7 C3 00 E8 CD 41 E7 ...F....F.....A.
E090: CD 8D E6 C3 97 E0 23 CD - 46 E7 54 5D 7A CD 67 E6 ......#.F.T]z.g.
E0A0: 7B CD 67 E6 CD 41 E7 1A - 67 CD 67 E6 CD 41 E7 CD {.g..A..g.g..A..
E0B0: 92 E6 EB DA 96 E0 77 BE - CA 96 E0 21 BB E7 C3 11 ......w....!....
E0C0: E7 CD 41 E7 CD 8D E6 EB - CD 41 E7 CD 8D E6 F3 CD ..A......A......
E0D0: 62 E6 D2 DB E0 21 AA E7 - C3 11 E7 CD 46 E7 7A CD b....!......F.z.
E0E0: 67 E6 7B CD 67 E6 3E 3A - CD 06 E7 CD 41 E7 01 10 g.{.g.>:....A...
E0F0: 00 D5 1A CD 67 E6 CD 41 - E7 3E 09 B9 C2 07 E1 3E ....g..A.>.....>
E100: 2D CD 06 E7 CD 41 E7 13 - 0D C2 F2 E0 CD 41 E7 D1 -....A.......A..
.

So, for those wishing to use the NorthStar Monitor with the ZCB, you should cut the jumper in E between 2 and 4 (default) and move it to 2 and 3. All other default jumpers are fine.

billdeg
March 30th, 2011, 04:08 PM
B at the . prompt will cause the computer to seek a disk to boot

MikeS
March 30th, 2011, 05:08 PM
So I took Mike's advice and read through the I/O port strapping again. Turns out G doesn't do what I need, but E does. Well, E will allow you to set on 4-byte address boundaries; that is, 00 and 01, 04 and 05, 08 and 09, et c. Except the ZCB mirrors the ports for the 8251, so strapping for 00 and 01 also places it at 02 and 03, our magic numbers from before. I changed the strapping, booted, and jumped into E000 from the SCI monitor:
Yeah, that's exactly what I was trying to explain; the default sets the serial port to 04 & 05 and the console is connected to a Flashwriter or a Bitstreamer I/O card, so you have to cut the trace from E1 to E4 and connect E1 to E3 instead if you want the console on the ZCB (with a standard monitor); I installed an IC socket in mine to make it easy to move the jumpers and switch the console back and forth.

What's a Dajen SCI?

glitch
March 30th, 2011, 05:24 PM
Yeah, I didn't understand the first time around about the port mirroring...that's why I thought 02 and 03 was an impossible combination. What's odd is that I cut the factory jumper for the serial port in group E...perhaps it was working with a Bitstreamer or other 8251-based serial board before?


What's a Dajen SCI?

Dajen == maker, SCI == System Central Interface. It's a S-100 board with a cassette port, two parallel chips (one channel of which can be used for a parallel ASCII keyboard), a 6850 ASIC, three sockets for 2708 EPROMs (two of which contain the monitor, the third can not only read 2708s but /program/ them too), and 256 bytes of RAM in 2x 2112 SRAMs. The monitor is pretty nice...I like it better than the Cromemco 4FDC monitor. The 2708 programming is also /really/ cool, especially since I was able to copy the monitor PROMs with it. There doesn't seem to be a ton of information on it, so I'm going to do a write-up and make the manual/ROM images available when I get a spare moment.

MikeS
March 30th, 2011, 05:34 PM
...So, for those wishing to use the NorthStar Monitor with the ZCB, you should cut the jumper in E between 2 and 4 (default) and move it to 2 and 3. All other default jumpers are fine.Did you mean 1-4 vs 1-3 by any chance (instead of 2-4/2-3)? It is confusing, since 1 and 2 would be pins 2 and 3 if there were a socket there...

MikeS
March 30th, 2011, 05:45 PM
My other VG MZ system uses a Z80 card with a PROM/RAM card instead of the ZCB combo card; I believe it also has the ability to program 2708s, so it'd be nice to sort out the intermittent problem on the PROM/RAM card. FWIW, both my systems have 64K and use the Micropolis FDC (Bootstrap PROM @F800 IIRC) and drives; the Tandon versions have the boot code in the monitor.

glitch
March 31st, 2011, 02:06 PM
Did you mean 1-4 vs 1-3 by any chance (instead of 2-4/2-3)? It is confusing, since 1 and 2 would be pins 2 and 3 if there were a socket there...

Yes, you're right: move 1-4 to 1-3.

billdeg
August 15th, 2011, 07:08 PM
Working on a DAJEN now, I see from this thread that I have to disable the autojump on the ZCB to allow the DAJEN to boot, etc.
bd

glitch
August 16th, 2011, 08:26 PM
Yep, disable the ZCB jump and enable the jump on the DAJEN. Alternately, put a Jump ROM in the ZCB's PROM socket with a jump to the SCI's base address (default 0xD000).

Is this the SCI I worked on, or have you found another?!

billdeg
August 19th, 2011, 07:36 PM
We already talked, but to wrap up this thread...for future reference to anyone with a DAJEN SCI

1. I set up a serial switch box. I plugged each card into the switch box using the ribbon cable

A: The ZCB
B: The SCI (with null modem adapter)

2. I loaded the system and did not disable the ZCB. It booted into the Northstar Monitor 1.5 as always (9600/8/N/1) and gave me the . prompt

3. I ran the command G D000 to jump to the SCI monitor

4. I switched to channel B, hit return, and got to the SCI > prompt. I switched the terminal to 9600/7/N/1.

(Since then I learned I could just boot the ZCB 7/N/1)

5. I was able to run commands using the SCI monitor

NEXT -
1. Try using the prom burner on the SCI
2. Try running the SCI in my Altair 8080 style, which is the original CPU intended by DAJEN for it's SCI board. I understand that the little jumper wire needs to be pulled out of the upper plug and put into the lower plug, in order to autojump to the monitor. In the upper plug position the autojump is disabled.

Bill

billdeg
October 30th, 2011, 04:50 PM
I have the ZCB jumpered as Jon describes here in this thread, and it boots to the monitor prompt using a generic California Computer Systems 2200 "mainframe" S-100 system. I can run the same dump as SystemGlitch from E000 E100 and I get the same exact output. I have a working Northstar horizon MDS-AD3 controller installed, attached to a working set of drives, with a working N* DOS 5 disk (in an external enclosure) - all tested with a northstar horizon. I have 40K in RAM plus what's on the monitor card.

When I run the "B" command the system hangs.

1. Would I be better to try a Vector Graphic disk controller with this configuration?
2. Is it possible to have the monitor boot and then initiate the DOS boot, or do I have to re-jumper the system to use the I/O of the N* DOS, losing the ability to use the monitor?

I don't have the ZCB manual, this may all be in there.

BIll

MikeS
October 30th, 2011, 06:24 PM
I don't have the ZCB manual, this may all be in there.
BIllTwo versions and a brochure on Howard's site:
http://www.hartetechnologies.com/manuals/Vector%20Graphics/

billdeg
October 30th, 2011, 06:59 PM
Two versions and a brochure on Howard's site:
http://www.hartetechnologies.com/manuals/Vector%20Graphics/

Actually I had the manual on my site..I should try to remember such things...but actually what I'd like is the manual for the Northstar monitor 1.5.

The question is - what control does one have over how the ZCB-driven northstar monitor works with a northstar drive controller? One thing I could try is to use the B command to boot the system with a Vector Graphics controller and disk/drive assuming that this is the default. I am guessing there is a flag or series of flags for many of the major brand controlers at the time. Or at least my wishful thinking that something called "northsar monitor 1.5" would have provision for a MDS controller. I have eliminated a lot of the variables by making sure the MDS controller, drive, cable, and disk work so now I just need to find the rest.

It is possible that I need another 8K of RAM to take the system up to 48K, as this was what the test North* system has.

Jon and I have the same goal I believe, to put together a portable diskette system for S-100 chassis.

glitch
October 30th, 2011, 07:28 PM
IIRC, the ZCB puts its boot ROM at 0xE000 - 0xEFFF, correct? If so, it'll interfere with the operation of the NorthStar floppy controller, which lives at 0xE800-0xE9FF. I'd dump the monitor ROM (you can use the monitor itself to do this) and see where it tries to jump to for the B command.

If the ROM monitor leaves a hole at 0xE800-0xE9FF, you could add /PHANTOM assertion to your NorthStar disk controller (I assume the MDS-AD* series doesn't have it...the MDC-A* series definitely doesn't). This would allow the NorthStar controller to map itself over anything else present. I've actually been looking into doing this with my NorthStar MDC controller so that I can make better use of upper memory...the MDC series provides a board select signal from the address decode PROM, which should suffice for driving /PHANTOM once it's inverted to the correct polarity (may be elsewhere on the board) and fed into something with an open collector output.

MikeS
October 31st, 2011, 08:18 AM
I'm not at home so it's inconvenient to check, but I believe the monitor source is in (at least) one of the Vector manuals; ISTR that it expects the controller to be at either F000 or F800.

billdeg
November 1st, 2011, 02:35 PM
I am going to spend more time with this tonight.

billdeg
November 1st, 2011, 04:36 PM
I checked...there's no code in the space after E700 but it appears the PROM locks out the remaining RAM addresses for internal use from e800-efff. The bootstrap code from the MDS-AD3 does not load into E800-Efff. When I test this space, I cannot write to it. I can however write to other locations using the ROM monitor, such as 0000-000f etc.



bd

glitch
November 1st, 2011, 05:07 PM
Does the ZCB assert /PHANTOM when the PROM is being read? If not, will it respond to /PHANTOM when the address is in the PROM range? If so, the /PHANTOM assertion circuit I mentioned previously would fit the application. Also, IIRC the ZCB has a 2732 4K x 8 EPROM in it at the moment...will it accept a 2716? If so, you can jumper it for a 2716, burn the monitor to a 2716 (it'll fit, sounds like), and that will solve the problem. /IF/ it properly addresses a 2716, you can map the EPROM to 0xE000 - 0xE7FF, stopping exactly where it needs to for the NorthStar controller (I'm sure that's no coincidence!).

EDIT: If you can use a 2716 and you don't have the capability to burn them, I do, so let me know!

billdeg
November 1st, 2011, 06:06 PM
I don't know if /PHANTOM is asserted. Do I check pin 68 for a voltage? Sorry I am not sure how to test. I need to check the ZCB manual.

It's very possible yes that the contents of the PROM after E7ff seem like open RAM but are actually part of the PROM as it was when the code was frozen into it, that had not occured to me.

I can try to make a 2708 set or a 2716 then.

This makes the most sense, you would think the northstar monitor would be made to work with the MDS bootstrap, and not to interfere with it. A PROM that stops at E7FF would probably do the trick.

Bill

glitch
November 1st, 2011, 07:14 PM
It looks like 2708s are going to be your answer -- page 2-3 of the VG ZCB manual: "There is a 1K gap in memory from E800H to EBFFH if standard jumpering is used." That is, the first two 2708s will be contiguous from E000H to E7FFH, and the third (if you use it) will be located at FC00H-FFFFH. Basically, just restore the EPROM jumpering to factory defaults.

You can even write the 2708s with the Dajen SCI!

billdeg
November 2nd, 2011, 08:04 AM
I can't wait to try it out tonight. I spent a lot of time finding two nice 1/2 height drives that work with the MDS controllers, and put them in a single full height external enclosure. I tested all of my various MDS controllers in a N* system to be sure I knew which were good and which were not, tested various types of N* OS disks and so on .. All so that I would have a nice little portable 2 drive system that I can use in any S-100 computer.

I wonder if the N* monitor will work in an 8080 system.

Bill

glitch
November 2nd, 2011, 08:50 AM
As I understand it, N* systems always used Z80 CPUs from the start, so I'd be surprised if their monitor was 8080-compatible. Easy enough to find out though -- with the monitor burned to two 2708s, you can put them in the Dajen SCI and set it for 0xE000 as long as you have something with a 8251 at the right address (I noted it somewhere else in this thread). The jumper area for addressing the SCI happens to be an 8-pin DIP pattern, so I replaced the wire jumpers on mine with a DIP switch to allow for easy/non-board-damaging changes of base address. IIRC, I had to remove a tantalum bypass cap to make the switch fit, but it can be omitted (plenty of bypass on the SCI already) or moved to the back of the board if you're worried about it.

billdeg
November 2nd, 2011, 09:00 AM
I guess one thing at a time, first get the monitor onto two 2708's and see if that'll allow the MDS to load code into RAM/boot a disk.

As far as whether the monitor will work in a 8080 system, you never know.

I am unaware whether the DAJEN will work in an 8080-based front panel system anyway.

Bill

glitch
November 2nd, 2011, 02:05 PM
I am unaware whether the DAJEN will work in an 8080-based front panel system anyway.

It should...we had mine (briefly) working in RetroHacker_'s IMSAI with a Cromemco ZPU.

billdeg
November 4th, 2011, 04:26 PM
The PROM in the ZCB is a 2716, not a 2732. Anyway, used the DAJEN to burn (attempt to) 2 2708 proms, but I had some trouble finding good EPROMS...but eventually I got the job done.

But then when I realized that I had a 2716 and not a 2732, I realized that it's the PHANTOM jumper that I need to activate, the 2716 should be fine as-is....right? I found where in the manual to change this, just have to do it. Will post when news.

billdeg
November 4th, 2011, 06:03 PM
With the PHANTOM jumper on or off, the bootstrap for the Northstar MDS does not load into E800, it's just a bunch of 1A 1A 1A...

I figure I would want it jumpered/connected, right? Wonder what's going on.

bd

billdeg
November 4th, 2011, 08:09 PM
I got the DAJEN to run on the Altair 8800a, but I need a line terminator, it konks out after a few minutes. I speculate there's line noise. I was surprised it worked at all.

Anyway just to recap using the ZCB in a newer generic S-100 system (CCS 2200)

1) the 2716 starts at E000 and runs through E7FF. That's the size of the 2716, if it starts at E000 physically it can't go past E7FF, right? The system consistently boots into the Northstar monitor 1.5.
2) with a MDS drive controller in the system nothing appears in E800- of the N* disk bootstrap program as you would expect.
3) I can't see how the one 2716 would be interfering with the system's ability to load the bootstrap into E800.
4) I tried this with PHANTOM jumpered and not jumpered (jumper C)

I repeated the same experiment with a few MDS controllers, although the one I have been using is known to work in a regular Northstar Horizon to boot disks.

I wonder what would happen if I put the ZCB, drive controller, and 24K+ RAM into a Northstar Horizon, wonder if that would boot via the motherboard serial port. Maybe the ZCB is jumpered or hot wired for that specific purpose.

BD

glitch
November 5th, 2011, 06:17 AM
The /PHANTOM jumper on the ZCB just allows the ZCB to assert /PHANTOM for its onboard ROMs. This is the opposite of what you want to do. While the 2716 is restricted to exactly 2KB max size, as you've concluded, the ZCB has multiple 2716 sockets. This results in the ZCB responding to, IIRC, 0xE000 - 0xFFFF if it is jumpered for 2716 operation. Even if there is no ROM in the socket, the bus drivers will activate and push whatever random state they're at onto the bus (hence, the 1A 1A 1A...).

If you place the board set in a NorthStar motherboard with built-in serial ports, there will probably be bus contention between the onboard port(s) and the serial port on the ZCB. This could, in the worst case, result in blown bus drivers when you try and read from both ports at once. In any case, it probably wouldn't work as expected.

Basically, from what I can gather from the ZCB manual, you'll need to use 2708s if you want a 1K hole at 0xE800 without any board rework. I'd think that since VG left a 1K hole there when using 2708s, it was probably intended for stock N* monitor ROMs and a N* disk controller.

billdeg
November 5th, 2011, 07:05 AM
The /PHANTOM jumper on the ZCB just allows the ZCB to assert /PHANTOM for its onboard ROMs. This is the opposite of what you want to do. While the 2716 is restricted to exactly 2KB max size, as you've concluded, the ZCB has multiple 2716 sockets. This results in the ZCB responding to, IIRC, 0xE000 - 0xFFFF if it is jumpered for 2716 operation. Even if there is no ROM in the socket, the bus drivers will activate and push whatever random state they're at onto the bus (hence, the 1A 1A 1A...).

If you place the board set in a NorthStar motherboard with built-in serial ports, there will probably be bus contention between the onboard port(s) and the serial port on the ZCB. This could, in the worst case, result in blown bus drivers when you try and read from both ports at once. In any case, it probably wouldn't work as expected.

Basically, from what I can gather from the ZCB manual, you'll need to use 2708s if you want a 1K hole at 0xE800 without any board rework. I'd think that since VG left a 1K hole there when using 2708s, it was probably intended for stock N* monitor ROMs and a N* disk controller.

OK, so I should cut the PHANTOM jumper and re-jumper for 2708's.

Although "the ends" are the same, I think you're not correct that *VG* intended use of stock 2708 N* monitor ROMs, as this was not their product. Instead, the N* Monitor 1.5 (I am guessing this is a independent shareware) was written or ported to the ZCB with the understanding the the VG is capable of a PROM/disk controller combo that would work outside of the N* system.

I have the ePROMs, I guess next I need to return the jumpers to a 2708 config. THere appear to be hacks on this board that are not part of the manual jumpering (on the back)...I will post a photo.

Bill

MikeS
November 5th, 2011, 08:04 AM
AFAIK E800 is where VG's 8" FD and HD controller ROMs normally live.

glitch
November 5th, 2011, 12:04 PM
AFAIK E800 is where VG's 8" FD and HD controller ROMs normally live.

Ah, yes that makes a lot more sense!

Bill, I think there were some modifications on that board...but IIRC they all agreed with a bugfix published in one of the VG ZCB manual revisions. Usually that's the first step I take in getting a board working -- I remove any user-applied fixes and see if there were any bugfixes published about the board. Definitely post pictures though.

billdeg
February 23rd, 2012, 07:11 PM
I have been studying the relationship between the ZCB and Northstar DOS. I have also figured out how to get the N* Bootstrap to load from the Northstar Monitor PROM in E000. The Rev 3 board that I have is set for 3 2716's by default, so I had to re-assign the memory location of the 2nd and 3rd to free up E800. Originally I assumed it was set like the rev 2 board, 2716/2708/2708 by default.

I have Northstar DOS 5 loading, but there is no terminal I/O because of the port incompatibility.

Northstar DOS uses ports 2 and 3. Basically to use the ZCB with Northstar DOS you have to either personalize your Northstar DOS to use ports 4 and 5, (or 6/7), OR disable the ZCB auto-jump to the Northstar prom and put the jumper in E to 1-4 from 1-3 (back to default).

I think I will put in a movable shunt so I can swap back and forth.

billdeg
February 23rd, 2012, 07:59 PM
I have been studying the relationship between the ZCB and Northstar DOS. I have also figured out how to get the N* Bootstrap to load from the Northstar Monitor PROM in E000. The Rev 3 board that I have is set for 3 2716's by default, so I had to re-assign the memory location of the 2nd and 3rd to free up E800. Originally I assumed it was set like the rev 2 board, 2716/2708/2708 by default.

I have Northstar DOS 5 loading, but there is no terminal I/O because of the port incompatibility.

Northstar DOS uses ports 2 and 3. Basically to use the ZCB with Northstar DOS you have to either personalize your Northstar DOS to use ports 4 and 5, (or 6/7), OR disable the ZCB auto-jump to the Northstar prom and put the jumper in E to 1-4 from 1-3 (back to default).

I think I will put in a movable shunt so I can swap back and forth.

UPDATE: This did not work, North * DOS did not autoboot to the MDS drive controller. I do not see a way to make CPU card to autoboot to the MDS's E800 "externally", is there? I suppose I could make a boot PROM for the ZCB that simply jumps to E800 automatically....I don't have a Z80-based front panel system so I can't do it manually.

My DAJEN was not functioning and I put it aside, maybe if I can wake it up I can find a way to call E800 or burn a ePROM to autojump the system to E800.