home *** CD-ROM | disk | FTP | other *** search
- Path: sparky!uunet!ferkel.ucsb.edu!ucsbcsl!network.ucsd.edu!usc!rpi!usenet.coe.montana.edu!news.u.washington.edu!uw-beaver!wiml
- From: wiml@cs.washington.edu (William Lewis)
- Newsgroups: alt.hackers
- Subject: Re: YAFP: TRS-80 Super Graphics
- Message-ID: <1992Aug30.032540.1104@beaver.cs.washington.edu>
- Date: 30 Aug 92 03:25:40 GMT
- References: <YAMAUCHI.92Aug29141341@fox.ces.cwru.edu>
- Sender: news@beaver.cs.washington.edu (USENET News System)
- Organization: Computer Science & Engineering, U. of Washington, Seattle
- Lines: 43
- Approved: By the Universal Temporal Irrelevancy Corps U.T.I.C
-
- In article <YAMAUCHI.92Aug29141341@fox.ces.cwru.edu> yamauchi@ces.cwru.edu (Brian Yamauchi) writes:
- >Now, you can delete your VARPTR/POKE commands, and whenever you want
- >to display your alien invader, simply PRINT A$ at the appropriate
- >point in the screen.
-
- The same trick was the standard way to run assembly language
- programs on the ZX81/Timex-Sinclair 1000 (and others of their ilk).
- Youd first write a program like this:
-
- 10 REM XXXXXXXXXXX....
- 20 FOR I=16514 TO 16823
- 30 INPUT A
- 40 POKE I,A
- 50 NEXT I
-
- (My sinclair basic is very rusty, so please excuse any weirdities.)
- You'd run it and enter the values for your ML program, which would
- get stored in the REM statement. Then you'd delete the input routine and
- replace it with the BASIC part of the real program.
-
- I ended up doing this often enough that for short programs I'd just
- type in the REM statement directly. This wasn't always possible
- unfortunately because of the Sinclair's bizarre character set (non-ASCII,
- of course!). The lower 128 characters were pretty normal --- numbers,
- letters (uppercase only), etc. But towards the upper end of the
- set were entire tokens --- "LET ", " TO ", etc. were all single characters.
- (The display memory was variable-sized to account for this, and also
- to save memory by not storing the righthand white space. In 1 or 2 K of
- RAM it's a useful technique...) But because of the mode-ful nature
- of the keyboard (probably why I use vi), "LET " would only be bound to
- any keys if you'd just entered a line number! At other times,
- the same key would be, I think, "L" (maybe "K"). The shift key would
- allow you to use other tokens like " TO " and "THEN". A graphics-mode
- key would let you enter the various "graphics" characters... When
- my membrane keyboard wore out and I cobbled on a "real" keyboard
- (from RS, probably), I'd memorized almost all of these bindings
- and hardly ever had to refer to the original keyboard... just as well,
- since the new keyboard didn't have quite the same wiring and the
- bottom row of letters was shifted over. Ahhh, memories. =8)
-
- I probably have a soft spot in my head for the Timex because it's
- the first computer (such as it was) that I really got any hands-on
- use of ...
-