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MAI Basic Four anyone?

vcm

vcm

Member
Joined
Dec 10, 2016
Messages
33
Location
Virginia
Just looking to see if anyone out there has any Basic/4 equipment in their collection. We have a complete system with documentation, disk packs, etc. At some point it would be nice to restore and see if it can run. I have never had much luck finding information about these systems online. Thanks in advance, looking forward to hearing from you!
 
My Dad brought home a Basic Four server and a few terminals back in the early 90s. The server had crashed and I was getting very good at fixing stuff so they figured they'd throw it at me. It took me weeks, but I did finally get the thing going. Took a while to realize it lierally ran on BASIC. :) I have very dim memories of it unfortunately and my Dad's company took it back once I got it working. I'll try and see if I can summon up any recollection of it. Was a neat 'little' system.
 
About six years ago I was offered one of the blue terminals from a setup but at the time had no idea what cataracts were and the assumption is they would not operate alike a regular RS-232 terminal if the rest of the hardware was missing so I regrettably passed on it.

220px-Basic_Four_terminal.jpg


I have not seen another one since.
 
Ours looks like the 4102 that RICM has. We have 2 of the removable disk pack drives that appear to be model 2500. They are 80 meg drives. I am going to some additional research on the CPU boards to try and determine the exact configuration. We have service manuals for the disk drives, but not for the CPU itself.

You can see some of the components on our web site:

http://www.vacomputermuseum.org/collections/hardware/mai-basic4-4102/
 
@ m_thompson

regarding your 4102, this seems to be the CPU/Disk controller for a 5120/730, i have the same one:

http://basicfour.de/mai510/pics/small/index.html

without disk drives, this one does not do much ;-)

However, the cpu and memory can be tested using a terminal (VDT boot). The cpu can be jumpered/switched to "boot from terminal". In that mode you can enter memory content and jump to that memory.

Here is a short description: http://basicfour.de/cpu/small/index.html

The code shown is for a 210, for a 510/730 the io address for the serial port differs. If you execute the code and the cpu goes to halt after about 2 seconds, your cpu basically works. I'm still looking to find the reference manuals for the 13xx cpu:

  • 1300 CPU Technical Manual
    M1300 Series CPU Organisation and Description Reference Manual

I figured out that the macrocode of the 13xx cpu's are similar to the ones used in the 1200 series. The 1200 series were not developed by basic four, they bought it from microdata. I started to adapt an assembler and wrote a small disassembler for the machine. The test code disassembles as:

Microdata 1600/21,821 disassembler 1.00, Armin Diehl <ad@ardiehl.de> October 8, 2015
0200 04 DIN ; Disable interrupts
0201 87FFBF LDX FFBFH ; Load 16 bit word to X (m=7)
0204 EFAF LDV AFH ; load variable length into A or AB (m=7)
0206 48 INA ; Increment A
0207 3900 OBA 00H,00H ; output byte from A (0x00)
0209 97D000 LDB D000H ; Load 16 bit word to X (m=7)
020C 49 INB ; Increment B
020D 1AFD NBZ 020CH ; Jump if B <> 0 (ofs: -3=0xfffffffd)
020F 1FF5 NAX 0206H ; Jump if A <> X (ofs: -11=0xfffffff5)
0211 660200 JMP 0200H ; Jump (m=6)
0214 00 HLT ; Halt cpu
 
Have you imaged the roms? I'd love an image to run on the Microdata 1600. Also a disk image would be useful of course.

I have (with help from Richard Swingwood) an emulator that runs the Microdata 1621, which is the base of the 1200 instruction set.

the firmware + disassembly that is above would be great to have, as I can run with disassembly, possibly also at the macro level.

thanks
Jim
 
Hello,
I have a Basic Four 7250 terminal. I want to use it as dumb terminal for my Linux workstation but the optional lower case display ROM is missing.
Do someone have such a ROM or at least a BIN so I can write it by my self or know where to get it?
Any help is welcome.
 
Ours is a 7270, and it has lower case capability. Is yours the older blue one?
 
One of our members (ard) contacted me months ago about the service manual for the MAI Basic Four S/10. I can't reply to him because his forum mailbox is full and won't accept any new messages.
So maybe this reply will get in his e:mail.

I FINALLY FOUND IT !!!!

I've been looking for this manual for months!

I will start scanning it this week. Give me a little time to scan the manual and I will post it on MediaFire for download.
 
Chuckster_in_Jax said:
One of our members (ard) contacted me months ago about the service manual for the MAI Basic Four S/10. I
I FINALLY FOUND IT !!!!

I've been looking for this manual for months!

I will start scanning it this week. Give me a little time to scan the manual and I will post it on MediaFire for download.
Click to expand...

Finally got the darn thing scanned in. Got a new All-In-One printer\scanner but had trouble with the scanning software.

Anyway here is the link: (Its's been OCR'd too!)

http://www.mediafire.com/file/htjtw...ice_Display_Terminal_Service_Manual_.pdf/file
 
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