Converting Spectrum code to zx80,81

A place to discuss the ZX80's and ZX81's younger brother - the Sinclair ZX Spectrum
Post Reply
Crayon21
Posts: 348
Joined: Sun Nov 04, 2018 2:33 am

Converting Spectrum code to zx80,81

Post by Crayon21 »

Apologies if this is in the wrong area

What changes would I need to make to convert a spectrum game to the 81 or 80?
any ideas?
In Heck, there are two options for perpetual torment:

Eat the Puckerberry and suffer for eternity:
drink nothing but a cocktail of The Last Dab and Mexican Cake blended and served with
habanero slices
:twisted:
Spinnetti
Posts: 253
Joined: Sat Sep 12, 2020 11:29 pm

Re: Converting Spectrum code to zx80,81

Post by Spinnetti »

Never tried it, but feels like it would just be easier to write from scratch.
Zeddy: ZX80, ZX81/ZXpand, TS1000/ZXpand, TS1500/Zxpand+
Speccy: 48k, +, +2, +3, TS2068, "Bare Metal" Pi, Next KS2, IF1/Microdrives/Vdrive/Light Gun/VGA-Joy
QL: Minerva/QL-VGA/Custom PSU
C5: 24v, LiFE battery, Disc brakes
User avatar
Paul
Posts: 1511
Joined: Thu May 27, 2010 8:15 am
Location: Germanys west end

Re: Converting Spectrum code to zx80,81

Post by Paul »

Easiest way would be to supply a ZX81 with the sponzy ROM. This is a spectrum ROM modified to run on a ZX81.
Pure basic still is a problem because spectrum has multiple commands on each line which have to be single commands per line.
Graphics is far enhanced compared to the ZX81.
So it's really easier to rewrite from scratch.
In theory, there is no difference between theory and practice. But, in practice, there is.
dr beep
Posts: 2060
Joined: Thu Jun 16, 2011 8:35 am
Location: Boxmeer

Re: Converting Spectrum code to zx80,81

Post by dr beep »

Crayon21 wrote: Wed May 25, 2022 8:30 am Apologies if this is in the wrong area

What changes would I need to make to convert a spectrum game to the 81 or 80?
any ideas?
I converted my Shogun game into a ZX81 game.
I had to alter the source on several points
1) skip use of IX and A'
2) make new display on screen
3) alter key reading

and your game needs to fit 16K
453BBBE9-55F0-4DFE-817C-849F91A28B22.png
Post Reply