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LATINDATA Multitech - Z80 & 6502 together. Yes... CP/M

R

RetroEdu

New Member
Joined
Jul 12, 2020
Messages
2
Location
Buenos Aires
Hi everybody!
Some good people from retrocomputingforum.com told me about you.

I'd like you to take a look at the link below.
Some history related to this PC.
When I was a kid, my first computer contact was with an Atari 2600 (obviously) and then TI-LOGO.
Then, CZ-1500 (16k ZX-81), C-64, MSX, PC, MAC and now... a DeLorean and back to the Ti-99. ha ha ha! First love.
While learning logo in school, some "old people" used computers for "big people". We weren't allowed to touch them. The computers...
In my memory, it had been saved as an early XT. The brand: LATINDATA. I treasured a brochure from that time.
A few days ago and 35 years later, I was looking at an Atari 65xe (I always wanted to have an ATARI and couldn't), and I came across THAT PC! YES! Now, I can touch it! :)
Then, I remembered the brochure!!!... 4 hours later, and 25 boxes checked, I found it. uff...
But surprise! It wasn't an IBM PC clone. It had a Z80, a 6502, and run CP/M. mmm... Very interesting machine! A Z80 processor and a 6502 for graphics. (see the brochure) It is in Spanish but the technical information is easily understandable.
Ok... short version: The owner of the PC (not mine yet), doesn't have a single diskette from that time. Ouch! The PC is in my house and I have no idea what it is. Maybe a rebranded Multitech. But which one!? I found some of the LATINDATA MPF-III (Multitech MPF-III) but nothing with a monitor with that PET like shape.
Before I start taking out screws and look inside (like I said, it's not mine), has anyone seen this PC before? At least one picture on the Internet? Maybe some Taiwanese friend former ACER worker? I think that recreating a floppy with CP/M for this machine is going to be a real headache!
Meanwhile, I sent an e-mail to the people of this remarkable museum today. If you ever visit Buenos Aires, be sure to check it out. I heard it's one of the best in the world but I don't know any others. :)
https://www.infobae.com/tendencias/...empo-de-las-computadoras-y-consolas-de-juego/
https://museodeinformatica.org.ar/proyectos/

Well, that's it. Any data, clue, or diskette will be welcome!

LATINDATA "Profesional" link:
https://drive.google.com/drive/folders/1qPHmxbnH_2F7prtdaphAVDdDp1w9lxLf?usp=sharing
 
I have one of these, but with a corrupt ROM.
might it be possible to get a copy of your ROMs? I should be able to make boot disks for this and could make you one?

Paul
 
Well, it's not about the right machine, but there seems to be some info here.

http://www.bitsavers.org/pdf/datapro/programmable_terminals/Datapro_C21_Ontel.pdf

Regarding the specific problem, there is mention here of what is probably the same floppy drive, which might help anyone trying to create a boot disk. The drive seems to be a Tandon model, an external unit with two drives. The 5.25" disks are referred to as being 500k capacity, which I'd think means an 80T (96tpi) format. Seems likely that the Ontel Amigo machine (from the same factory) would use the same format as the disks for the 'terminal' device listed in the brochure.

Geoff
 
Here's my two cents, while extending the z88dk "appmake" tool found an interesting tool called "ALIEN" (being ALIENC.COM the component I focused on) capable of reading several CP/M disk formats. Like other similar contemporary tools it existed in both MSDOS and CP/M version.

By doing a little bit of reverse engineering I could track down most of the configuration parameters, I could then cross-check my resulting disk images by running ALIENC on them. The result is not 100% guaranteed because a Microbee emulator won't be identical to the harware of the target system fod which that disk image was for, but it is very close.

The Visual 1050 disk format is well known, z88dk-appmake is set up in this way:

.disk_mode = MFM250,
.sectors_per_track = 10,
.tracks = 80,
.sides = 1,
.sector_size = 512,
.boottracks = 2,
.directory_entries = 128,
.extent_size = 2048,
.byte_size_extents = 1,
.first_sector_offset = 1,
(no skew)


For the Cortex CW/P I discovered the following to be correctly read by "ALIENC":

.disk_mode = MFM250,
.sectors_per_track = 10,
(1) .tracks = 40,
.sides = 1,
.sector_size = 512,
.boottracks = 2,
(2) .directory_entries = 64,
(2) .extent_size = 1024,
.byte_size_extents = 1,
.first_sector_offset = 1,
(no skew)


Supposing that most of the harware was left unchanged, if the V1050 disks do not boot, you could proceed by steps, first of all trying to put the first half of a Visual 1050 boot disk in a 40 tracks formatted floppy disk. ImageDisk and other tools can help in the disk image manipulation.

If the boot process will succeed, then it could be possible to hand-edit the DPB in the BIOS tracks and rebuild a system capable of working in 40 tracks mode. The files could be pulled in a blank disk image via cpmtools, but I'd proceed by steps.
 
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