View Full Version : Palto Alto Tiny Basic was running from CP/M ?

July 18th, 2010, 08:32 AM
Palto Alto Tiny Basic was running from CP/M or seperate floppy ?

July 18th, 2010, 08:45 AM
PA Tiny BASIC (V1.0, 1976) used CP/M (probably V1.4) for its disk operations. However, there are many variations of Tiny BASIC, some of which may use different operating environments.

Dwight Elvey
July 19th, 2010, 01:06 PM
There is a listing on the web for a PA TinyBasic that ran on the Poly88 in ROM. It is relatively
easy to make ROM code run in RAM. That particular TB had the ability to connect new functions
or procedures. I wrote some for mine to do PEEK and POKE as well as a SAVE that wrote
to a tape drive. I used the Poly88's autostart to both load the BASIC file and start TB.
In any case, it should be easy to connect it to most anything that has a terminal in/out.

July 24th, 2010, 01:09 AM
The original PATB wasn't for CP/M, it was intended for a 2K ROM or loading into RAM from paper tape via TTY. There were several versions ported to CP/M, though. The original was written with only two I/O routines, OUTC & CHKIO, character-oriented routines for talking to a TTY via OUT 01 and INP 00/INP 01 on the 8080. There was no support for a filesystem. The first addendum to PATB published was a routine that allowed the TTY to be switched off and a Processor Technology VDM board could be used instead.

PATB appeared in DDJ's May 1976 issue, which I recall appearing in early June. The VDM addition came in the June/July issue, which I recall appearing about the 4th of July. If the original source isn't on the web, let me know. I've scanned it and the addendum from my old DDJs and put it in a PDF, though it's rather large. I'm better at such things now, so if it's not available elsewhere I'll try to post it in a reasonably-sized PDF. It really does make good reading.

Dwight Elvey
July 24th, 2010, 09:51 PM
The version for the Poly88 would be quite easy to add calls for
files and such. It was made to be extended. Like I said, I
patched on a SAVE that wrote to tape. One could just as
easily added file commands.

July 25th, 2010, 08:13 AM
Tiny BASIC pre-dates CP/M (First writeup in Dobbs was June '76) and it was a "movement" first discussed in the People's Computer Company newsletters before Dr Dobb' first issue started. Dr. Dobbs was created as an off-shoot to the People's Computer Company newsletter to focus solely (at first) on Tiny BASIC as an alternative to MicroSoft Basic, that could be run in as little as 1K. There were many "tiny basics" in 1976 to choose from, depending on the processor, video card, etc.

The version I use the most is called VTL-2, which was made to run on the Altair 680, and it was typically ported to three 2708 ePROMs, leaving the user with an addition 256 bytes to play with for programs.


Running Tiny BASIC within CP/M is not the same thing as running later versions of MBASIC within CP/M. Tiny BASIC was supposed to be run independently of any operating system, there really was no microcomputer "operating system" when Tiny BASIC was first introduced. Things happened really fast at this time, so the original need for a tiny basic after 1977 kind of diminished. It was really only the big thing in 1975-76 when all one had was RAM monitor programs to interface with a computer. CP/M needed more RAM than 1-4K for effective use.