Basic Four / was Re: Microdata disk/tape images

Brent Hilpert hilpert at
Sat Feb 7 18:28:53 CST 2015

On 2015-Feb-07, at 4:00 PM, jwsmobile wrote:
> On 2/7/2015 3:51 AM, Armin Diehl wrote:
>> On 02/05/2015 10:19 PM, Ian McLaughlin wrote:
>>> Long shot, but does anyone know of any available disk/tape/paper tape/ROM images for any of the Microdata machines (800/1600) or the relatives (Intertechnique Multi-8/Multi-4, MAI Basic Four BB-II)?
>>> There’s a bit of documentation available - Bitsavers has a bit, and I have some MAI documentation that I’m in the process of scanning.  I’m toying with the idea of emulating this machine, but I’m having difficulty locating any software for it.
>>> Thanks in advance.
>>> Ian
>> Not exactly that, however, i may have something for BB-IV but i think these ones used cpu's developed by basic four. I have one 14" harddisk from a model 210 as well as a disk pack for a basic four 510, both should be bootable. I have the machines/drives as well but not yet tried to fire them up. The 210 came with a tape 1/4" drive but i dont have any tapes.
>> I also thought about writing an emulator but i have not yet found the manuals for the cpus used (1300 CPU Technical Manual / M1300 Series CPU Organisation and Description Reference Manual). I have scanned the available documentation and it is saved at Al's bitsaves site (pdf/mai/).
>> The 210:
>> The 510:
> These are very nice photos.  Both of your systems appear to be on the Microdata form factor, and if you were to look at the edge card connector, it is probably a 130 pin (65 x 2) connector.74181 ALU chips.  I see a lot of what appears to be the scale logic that a 1600 type CPU or an advanced design could use on that the boards your photographed.
> Also the of the 4 switches are they all dual position, or are some momentary?  i believe that Basic 4 in this series of system kept the 4 sense switches of the 1600 in their hardware with similar functions across all variations.
> The QIC drives were emerging in the late 70's and early 80's as a storage media, but in the era of the original blue systems with Microdata CPUs they were not around.
> Very nice systems.
> I don't know how much Century Trident info I have to offer, but I may have documents if Bitsavers does not.  I just got a stash of documentation which comes from the direction of Pick Systems documentation.  They used the 80, 100 and I think 200mb Tridents for their Evolution systems.

I programmed for a Microdata/REALITY system as a teenager ca. 1977 (business accounting applications), and I remember Basic Four as another competitor / minicomputer company in the business market, but never knew much about them.

Can you (or anyone) briefly describe what distinguished Basic Four in the marketplace? What were they offering that was particular or special or 'interesting'?, esp. if they were using the same CPU initially?

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