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Mohawk Data Sciences (MDS) series 21, anyone know?

D

Denniske1976

Experienced Member
Joined
Jan 17, 2011
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480
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The Netherlands
Hi all,

I've acquired a Mohawk Data Sciences series 21 machine last friday (and it's still in my car hehe). I was wondering if anyone has any info on it. A web search did give me a wiki and facebook page with some info, I only know them from the MDS datarecorders. never even knew they did computers. Also found one swedish or finnish site that had some info (not readable for me, though) and a picture of what I have in my car now ;-)

It's quite a big brown/yellow computer, two sections: one is the screen with (I think) also the CPU in it, keyboard is fixed via a wire to this unit. The other one is a big heavy unit with two 8 inch floppy drives in it that's connected via a flat cable to the other unit (kinda like the IBM 5120 had IIRC). The only thing I was able to find out is that the series 21 was a Word Processing system.

Unfortunately the keyboard is missing about 12 keys and I don't think I'll be able to find them anywhere... so I was actually thinking about taking it apart and seeing what's in it, always nice to have one or two 8" floppy drives on display and maybe there's some nice memory or CPU cards in it too ;-) Dunno yet since I haven't been able to get it out of my car yet.

Or maybe should I get this thing restored (as a hobby of course) since it's uber-rare and very special?? I know MDS wasn't around that long, they got sold somewhere in the late 80s I think.

Anyway, any help or info on this thing would be very appreciated. The only thing it resembles to IMHO is some IBM Data Processing system we had at school, also two units: one CPU/screen unit and another unit with two 8" drives, only that one was white and more "stylish" (rounded edges etc, very "2001: A Space Odyssey") ;-)

Thanx for reading and have a good one!

Dennis
 
It's a general purpose data collection and distribution system

It's a general purpose data collection and distribution system

I worked for the MDS subsidiary in Johannesburg South Africa in the '80s. The Series 21 was the successor to the MDS 2400 and 1200 series, which were key entry and communication devices. The Series 21 was one of the first minicomputers to employ a microprocessor, the Zilog Z80 I think. The CPU was on a circuit board in the main cabinet, as were the terminal controllers, which connected up to 16 (in the later models) very dumb terminals via coax cable.

In South Africa at least, it was mostly employed as a data entry terminal using variations of an application called Formatted Data Entry (FDE), and supported a variety of communication protocols to upload this data to IBM, ICL, Sperry, Univac and Burroughs mainframes. Most of the applications were written in MOBOL (Mohawk Business Oriented Language), which looked nothing like COBOL.

Apart from its primary market, the Series 21 was flexible enough to perform office functions such as word processing and accounting. It featured quite well in office automation until the arrival of the PC.

Hope this helps. Anyone else out there with experience on the S21?
 
Denniske1976 and Mervyng, hi,

Here is another one with experience of the MDS 21. I worked for the MDS representative in Finland (Datasaab-Valmet) with MDS machines 1975 to 1978, and the for the MDS subsidiary in South Africa 1978 to 1980. I programmed quite a lot in MOBOL.
I did actually write a word processing program for the MDS 21, that was used by Mission Mailing in Durban. It also so happened that I wrote the first version of the MDS 21 accounting system (as far as I know), and this was delivered to the accounting bureau Richardson Reid & Partners (hope I remember the name right) in Johannesburg.
Yep, I had quite a lot of fun with the MDS 1200, MDS 2400 and the MDS 21.

Bertil Osterberg
bertil@icon.co.za
PO Box 891404, Lyndhurst 2106, South Africa
 
Mohawk Data Sciences Series 21

Mohawk Data Sciences Series 21

:wow::wow:
BertilGunnar said:
Denniske1976 and Mervyng, hi,

Here is another one with experience of the MDS 21. I worked for the MDS representative in Finland (Datasaab-Valmet) with MDS machines 1975 to 1978, and the for the MDS subsidiary in South Africa 1978 to 1980. I programmed quite a lot in MOBOL.
I did actually write a word processing program for the MDS 21, that was used by Mission Mailing in Durban. It also so happened that I wrote the first version of the MDS 21 accounting system (as far as I know), and this was delivered to the accounting bureau Richardson Reid & Partners (hope I remember the name right) in Johannesburg.
Yep, I had quite a lot of fun with the MDS 1200, MDS 2400 and the MDS 21.

Bertil Osterberg
bertil@icon.co.za
PO Box 891404, Lyndhurst 2106, South Africa
Click to expand...

Denniske1976 said:
Hi all,

I've acquired a Mohawk Data Sciences series 21 machine last friday (and it's still in my car hehe). I was wondering if anyone has any info on it. A web search did give me a wiki and facebook page with some info, I only know them from the MDS datarecorders. never even knew they did computers. Also found one swedish or finnish site that had some info (not readable for me, though) and a picture of what I have in my car now ;-)

It's quite a big brown/yellow computer, two sections: one is the screen with (I think) also the CPU in it, keyboard is fixed via a wire to this unit. The other one is a big heavy unit with two 8 inch floppy drives in it that's connected via a flat cable to the other unit (kinda like the IBM 5120 had IIRC). The only thing I was able to find out is that the series 21 was a Word Processing system.

Unfortunately the keyboard is missing about 12 keys and I don't think I'll be able to find them anywhere... so I was actually thinking about taking it apart and seeing what's in it, always nice to have one or two 8" floppy drives on display and maybe there's some nice memory or CPU cards in it too ;-) Dunno yet since I haven't been able to get it out of my car yet.

Or maybe should I get this thing restored (as a hobby of course) since it's uber-rare and very special?? I know MDS wasn't around that long, they got sold somewhere in the late 80s I think.

Anyway, any help or info on this thing would be very appreciated. The only thing it resembles to IMHO is some IBM Data Processing system we had at school, also two units: one CPU/screen unit and another unit with two 8" drives, only that one was white and more "stylish" (rounded edges etc, very "2001: A Space Odyssey") ;-)

Thanx for reading and have a good one!

Dennis
Click to expand...
 
Worked for MDS, from 1968 to 1990. The Series 21 was a Z 80 based multi user, Distributive Data Processing System. it provided data entry, program application to each terminal keyboard unit attached to the CPU. All key info was sent to the processor during crt refresh times as all display info came from controllers in CPU unit. It had many communication emulators as well as word processing, accounting and COBOL like MOBOL programming available. Communications and print operations could be run as detached background programs. It also had a floating background that could be picked up by a key station to perform an operation and then released to be available to another operator. Base system could be expanded to 16 keystations and a variety of peripherals.

Last versions included things like multi processors that could be hot swapped if one failed. Used memory technology that allowed double byte access on one cycle.
 
tingo said:
What other series did Mohawk make?
Click to expand...

It all started with Data recorders, first 7 track key to tape, then 9 track, followed by the 2400 and 1200 key to disk systems, with peripheral options, extra disks, tape drives and printers, comms, up to 20 input terminals, then came the Series 21 key to disk system, that could also have comms, tape drives and printers, they weren't really word processing systems, more data entry, payroll, accounting and that sort of thing. The last hurrah was the Hero, an IBM compatible PC, a sort of modular system that you could add to, it was a bit like Lego! the units locking together.
MDS in the states then went belly up, the company Mohawk survived for a few more years in the UK selling non impact printers from Group Bull of France.
Steve
 
Thanks for the information. When I worked in the Army (many years ago) here in Norway, they had a specialized logistics / accounting system that everyone referred to as "Mohawk". It was what I think of as "half-size refrigerator" size, that is it fit under or beside a desk, and it had two floppy disk drives (I can't remember if they were 8 or 5.25 inch) and a terminal. IIRC, these things booted off one floppy, and stored the data on the other. Each system was standalone; "networking" was via floppies in the mail. :)
I don't know more about it, and I don't have pictures or anything else. I worked in IT then, but (part of) my job was operating the replacement system, which ran Unix and was networked (fibre optic all the way to the transceiver on the back of the servers, and the WAN part was encrypted).
 
Series 21, MOBOL, EZCoder

Series 21, MOBOL, EZCoder

Denniske1976 said:
Hi all,

I've acquired a Mohawk Data Sciences series 21 machine last friday (and it's still in my car hehe). I was wondering if anyone has any info on it. A web search did give me a wiki and facebook page with some info, I only know them from the MDS datarecorders. never even knew they did computers. Also found one swedish or finnish site that had some info (not readable for me, though) and a picture of what I have in my car now ;-)

It's quite a big brown/yellow computer, two sections: one is the screen with (I think) also the CPU in it, keyboard is fixed via a wire to this unit. The other one is a big heavy unit with two 8 inch floppy drives in it that's connected via a flat cable to the other unit (kinda like the IBM 5120 had IIRC). The only thing I was able to find out is that the series 21 was a Word Processing system.

Unfortunately the keyboard is missing about 12 keys and I don't think I'll be able to find them anywhere... so I was actually thinking about taking it apart and seeing what's in it, always nice to have one or two 8" floppy drives on display and maybe there's some nice memory or CPU cards in it too ;-) Dunno yet since I haven't been able to get it out of my car yet.

Or maybe should I get this thing restored (as a hobby of course) since it's uber-rare and very special?? I know MDS wasn't around that long, they got sold somewhere in the late 80s I think.

Anyway, any help or info on this thing would be very appreciated. The only thing it resembles to IMHO is some IBM Data Processing system we had at school, also two units: one CPU/screen unit and another unit with two 8" drives, only that one was white and more "stylish" (rounded edges etc, very "2001: A Space Odyssey") ;-)

Thanx for reading and have a good one!

Dennis
Click to expand...

Let me start by saying that I worked for MDS from about 1977 to 1980. Initially I worked out of New York City and then as a National Systems Analyst out of the MDS Education Center in Cherry Hill, NJ. I spent most of that time specializing on the Series 21. I wrote EZCoder, a full screen editor/IDE for the Series 21 in 1977 or 1978. More about that later.

MDS was first and foremost a data capture, data communications company. Besides the famous key to tape units, MDS marketed the 1200 and 2400 models. These had Atron CPUs and core memory. The Series 21 had, I believe, a Zilog Z80 CPU, possibly an Intel 8080. The Series 21 box supported 1 to 4 workstations, each consisting of a keyboard and a CRT display unit. The display was capable of either displaying 480? large or 1920? small characters. The Series 21 shipped with a utility which allowed operators to define 80 characters of punch card fields and then perform data entry.

MOBOL, a general business language compiler may have been an optional extra. The language allowed screen layout definition and program control when fields were entered or exited. EZCoder, which I wrote on my own time and left when I departed MDS, allowed users to enter MOBOL code in full screen mode, chain to the compiler and then interactively go through errors in the compiler listing. Since 3741 floppies only supported sequential, fixed length records procedures were implemented to allow the insertion and deletion (free space compression) of records.

I probably have a copy of EZCoder on floppy so if you get (got) the box running let me know. I also have the EZCoder source and maybe more. I believe that the Series 21 used the EBCDIC code set for data although the OS and compiler were built in CPM which used ASCII.

Wish I remembered more, but we're talking 35 years ago. Good luck.
 
Hi guys,

Been some time, but thanx for all the info... indeed the machine has a Z80 CPU (actually a MOSTEK MK3880N-4, datecode 8145). The machine is still sitting here, since I can't find any part to restore it. So unfortunately I don't think this is gonna be up and running again :blush:

But still, it's a nice read here, from a machine I didn't know anything about. So thanks again everyone.

Dennis
 
Denniske1976 said:
The machine is still sitting here, since I can't find any part to restore it. So unfortunately I don't think this is gonna be up and running again :blush:
Click to expand...
What does it need? Got a picture of the keyboard? I've still got some stuff from MDS equipment I scrapped years ago, you ever know...
 
Last worked on Series 21 in 90's. Last customer was Ministry of Transportation in Ontario, Canada. System requires CPU, MEM and DULS(for terminals) pcbs to boot. IPL diskettes were in pairs for MTO. Most common problem was head load pad wearing out on diskette drives. Sometimes diskette track 0 alignment would go out and R/W carriage home screw required adjustment, required oscilloscope and alignment diskette to properly adjust, but got to point where just let R/W head go to home position and adjust collar stop for quick fix on the fly. Common problem also ##33 error diskette load usually fixed by reset. Another common problem was memory IC replacement, which required diagnostic to locate offending chip(carried spare mem chips).
 
I was Tech Support for Mohawk in South Africa from the day the company opened there in 1972 until I left in December 1978. The Series 21 was a real piece of junk. Prior to this device the main product of the company was the System 2400 which was a mini-computer system of kludged-together units built by OEM's that Mohawk USA acquired with the money made from the data recorder success.

At the heart of the 2400 was the Atron 501/502 CPU which had a 16-bit Address Bus and 8-bit Data Bus. It's architecture favoured the moving of blocks of data. The 2400 came in 2 basic flavours - the Data Capture application - when a mux connected to a raft of punch data terminals - or a sort of off-line printing station - designed to take the print jobs away from mainframe computers and so save rental time and costs. For storage in the data capture app the system had a 10MB single-platter disc drive from Diablo in Arizona. There were also some 9-track tape drives in both NRZI 800bpi and Phase Encoded 1600bpi.

The 1200 was just a 2400 squeezed into 1 box. There were a few limits set so as not to kill off the 2400 market potential.

The big problem with the data capture app was that the punch terminals only had a 240 character screen - a format inherited from the key-to-tape units of previous years, and the industry was moving towards bigger screens. The series 21 attempted to address this issue.

As I recall the first generation of the S21 was Intel 8080 based. There was no Operating System on the S21 (or on most small systems) in those days. You loaded the app and it contained all OS functions in the main code. The developers of the S21 wrote themselves an 8080 assembler which used tri-octal notation. This was an inheritance from the 2400 because the Atrom 501/502 processor architecture was ideally suited to tri-octal notation.

If I remember right the S21 was first launched in 1977, at a time when I was already woking part-time (read all night every night) on my own product, and I had very little interest in it, knowing that my days at Mohawk were numbered. Remeber this was prior to Charlie Chaplin unpacking the IBM PC on TV and there was total choas in the computer business, with no standards of any sort in place. In those long-ago days the hardware manufacturers had to supply all the software as well.
 
Fyko said:
I was Tech Support for Mohawk in South Africa from the day the company opened there in 1972 until I left in December 1978. The Series 21 was a real piece of junk.
Click to expand...

That's a little extreme. As a user of the MDS Series 21 back in the early through late '80s, we were able to do quite a bit with the ones we had. One supported 8 data entry stations, BSC2780/BSC3780/NACHA communications, Word Processing, along with multiple custom programs written in MOBOL. Our second system was basicall communications only along with WPS. Custom Cobol programming allowed us to allocate and send files to the mainframe or retrieve files from the mainframe which meant we did not have to rely on tapes for most of our datacom. Our shop ran 18 hours a day on the Series 21 and for the most part, it ran without issue. I'm still amazed at what an 8080 running at 4.77Mhz could do.

Junk it was not.

--
Mike
 
That could very well be. After I left the bank I was working at, they were eventually donated to a career center to be used for date entry training.

--
Mike
 
Al, thanks for the links to the Series 21 docs. I wasn't introduced to the MDS Series 21 until 1982 and I *proudly* remember surviving the 13.J7 software release. :)

--
Mike
 
I don't think that I can be much help but I worked for MDS in the late 70s as an analyst in Tampa. I programmed in MOBOL, Mohawk Business Oriented Language. The series 21 was almost identical to their data entry machine. I believe that the only real difference was Grounding a wire to the case to prohibit the programming option.
 
I was a principal consultant for Mohawk (previously MDS) in the UK and responsible for Release 13. I also programmed in MOBOL, COBOL and assembler on the Series 21. I have a lot of knowledge (if I can still remember it!) and will start with a bit here and then if anyone is interested I'll add more.

The Series 21 consisted of several models 2120 (none programmable, 2140, 2150 and I think a 2160. Early models had the Intel 8086 that was clocked at 750KHz and later at 1MHZ. In later years the Zilog Z80 first at 2MHz then 4 and I think 6 just before Mohawk went bust. The early models supported 4 concurrent keystations each running the same application such as FDE (formatted Data Entry) and a floating background application that would flash a message when action was needed and could be serviced by any operator. The background application was usually a batch communications process but could also be things such as a batch print job. Later machines with R13 could support up to 16 keystations and also run MOBOL, COBOL and CPM concurrently (only three keystations due to processor power) that latter o/s was for Lotus123. Towards the end a compact desktop S21 (can't remember the model) was produced that was a self contained all in one i.e single screen only.

The Series 21 was designed by Gene Amdahl after he left IBM (he designed the S/360 mainframe) and then set up his own company. Thats why the Series 21 with a microprocessor had a mainframe like architecture that could run multiple tasks concurrently. It also explains why it was so communications orientated. The 8 inch disk drive from Shugart was IBM 3142 compatible and the screen had both a 480 (12 lines by 40 characters) and 1920 (24 lines by 80 characters) modes so that it could emulate IBM machines such as 2780, 3780, 3142, 3270, Hasp, 8100 etc. Also Univac 1004 and in the UK my colleague (sadly no longer with us) wrote an ICL 7502 emulator for CO2/CO3.

Early models of the S21 could only support 64KB of RAM and the minimum configuration was 48KB. You must remember in those days hardware was very expensive and the basic machine started around 20K plus GBP and a usuable configuration around 40K to 80K GBP and that was in the '80s! Of the 64KB of RAM 32KB was allocated to the data area of MOBOL and 16 or 32KB to the MOBOL application code. MOBOL (Mohawk Business Orientated Language) was an interpretated language that had to be compiled to pseudo code. This made the programs very compact. Later models could take up to 256KB of RAM and some may be wondering how come as te 8086 and Z80 had a 16 bit address bus that can only get up to 64KB. Remember it had a mainframe like architecture and a technique using hardware relocation registers fooled the processer into thinking it only had 64KB.

Early machines didn't have a hard disk drive but two 8 inch diskette drives. One held the operating system that was used to IPL the machine and the second to load applications and sore data etc. Once booted up and an applivation was loaded both drives could be used say to make a backup of one diskette to another. These early machines would also support tape drives 7/8/9 track. Another colleague (also sadly no longer with us) wrote 'Burster' that would handle the ICL mainframe 6 bit Byte format tapes. Then hardrives appeared built in the same size style case as the S21. First was a 2.5MB removable disk about 16 inch in diameter Then a fixed 10MB and the last drive had a 13MB removable disk and 13, 26 or 39MB fixed disk.

There is more and if anyone has a question just fire away.

Cheers,

MN
 
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