9

archive.org's DG collection has Single User BASIC and Extended BASIC manuals, but no BB manual. Does anyone have a PDF?

The underlying question... the earliest mention of BB I can find is from a 1977 ComputerWorld article announcing its release. This includes some rather confusing language about a "double-precision integer arithmetic facility". "double precision" and "integer" are not normally seen in the same statement.

It also states that it was based on the same "research" as Extended BASIC. Extended BASIC includes a complete FP system, and FP libraries and/or hardware are a standard part of DG systems of the era.

I strongly suspect they are actually referring to a BCD or fixed-point system. I find it difficult to believe that any business-oriented language would not have some way to handle pennies, especially considering they include output formatting for dollar formats.

Can anyone shed some light on this?

5
  • It is very confusing. If "double precision integer" meant what is more conventionally called "long int" (and "precision" meant what we call "range"!), you'd expect 32 bits giving a range of +/- 2 billion, not a lousy 21 million. If the BASIC does all its arithmetic in floating-point, you'd expect DG double-precision to be able to handle 56-bit integers exactly, unless there's some subtlety about base-16 floating point I don't understand. Dec 27, 2021 at 22:33
  • 3
    @another-dave But with a .3 decimal fixed point format the range of a signed 32-bit integer would indeed be around 21 million.
    – WimC
    Dec 28, 2021 at 9:01
  • DG BB does not have any floating point. Everything is in integers: single and double precision. You basically scale up all the calcs. Eg for finance, do everything in cents/pence etc and then convert to dollars/pounds before display.
    – cup
    Dec 28, 2021 at 17:12
  • @cup - then what does "double precision" refer to? 32-bit integers? Then why is the range so small? Dec 29, 2021 at 21:55
  • DG Novas and Eclipses were 16-bit machines in the 70s. Double precision refers to 32-bit integers. In those days, 32 bit integers were considered big.
    – cup
    Dec 29, 2021 at 22:34

1 Answer 1

1

I have a few Data General manuals, mainly old versions of manuals I would have trashed, but the collection does include Business BASIC and their standard Extended BASIC (upon which it was based, e.g. the STMA command is obviously based on the UCALL in Standard BASIC).

And yes, DG Business BASIC (which was continued by another company, and its origins involve yet another company - was it TAG Associates??) used only integer arithmetic (with DG-supplied routines to format fractions, so you could work with dollars and cents, for example), because the aim was to avoid round-off errors. There was a triple-word precision option, as I recall.

Despite the integer limitation it was a pretty good system, with ISAM built-ins, lots of admin tools, and we ran up to 9 terminals at one time off one Data General Nova (not Eclipse!) computer with 256K of RAM and about 50Mb of disk space. A pretty big Business BASIC program would be about 14 kilobytes, because it converted the program text down to a pretty efficient set of codes, using Reverse Polish, etc. It was very happy to work with a big range of non-DG terminals, such as ADM, Hazeltine, Qume and especially Televideo, as well as a few Dasher D2's and both a DG10 and Intecolor graphics PC acting as a terminal.

There used to be a huge selection of DG manuals online but I cannot find them now. One I do have is for the DG/L language, which got around the limited precision (even though double and triple word precision was thought big at the time) by allowing many bytes per variable (might have been 256??).

4
  • Specs for the Nova must have changed since I last used it (1979). At that time, the Novas could only take one terminal and not more than 16K RAM. The Dashers I used had metallic keyboard casings - used to get static shocks from them.
    – cup
    Apr 18 at 12:07
  • I used a Nova 3/12 with MMU (memory management unit) from around 1979, which could take 32K Words (64Kbytes) before adding an MMU and two TTYs before adding a ULM or ALM or comms chassis to take more serial lines. Even the MP/200 microNOVA (says 1978 on the pcb) could take 2 serial lines plus more with a mux board. The tilt/swivel Dasher 6053 terminals never gave us electric shocks - I wonder if you had an earthing problem? I have a Nova 3 in my garage plus quite a few manuals if anyone wants more information.
    – user235510
    Apr 19 at 20:58
  • The number of memory boards that could be added depended on the number of slots in the chassis - that, plus the fact that the very earliest NOVA computers could only take magnetic memory(!!) that came in (I think) 16Kwords maximum, might be why you fond that limit, or it could have simply been the machine was bought with small memory boards that would have to be swapped out to put in larger ones, possibly making it uneconomical to upgrade. Nova 3/4 machines had only 4 slots and they could easily have all been used for IO boards.
    – user235510
    Apr 19 at 21:04
  • Can't remember much about them: one had a brown chassis and had 8K, the other had a blue chassis. The brown one had all sorts: Fortran, Assembler and other strange stuff that was only used by the Computer Science dept. The blue one was at least 4 years old when I started using it: only had Business Basic. I remember thinking - why would anyone get a machine that only did integer arithmetic for an engineering dept.
    – cup
    Apr 19 at 21:14

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.