Search found 97 matches

by Fruitcake
Sat Jan 13, 2018 1:22 pm
Forum: Hardware
Topic: Chroma 81 - SCART and Colour interface for the ZX81
Replies: 133
Views: 8495

Re: Chroma 81 - SCART and Colour interface for the ZX81

It's no big issue, but do you know why in the EightyOne emulator the PC's cursor keys worked with the previous version, but not with this one? Here both keys move the base to the left. It's no big problem as this seems to affect only the emulator. The patch checked for the standard game keys (SHIFT...
by Fruitcake
Fri Jan 12, 2018 2:03 pm
Forum: Hardware
Topic: Chroma 81 - SCART and Colour interface for the ZX81
Replies: 133
Views: 8495

Re: Chroma 81 - SCART and Colour interface for the ZX81

It sounds like you've put a lot of thought into the colours used and so I say run with it as you intend.

Attached is a new patched version of the game that supports both the standard control keys and the cursor control keys.
spaceraiders(standard_and_cursor_keys).zip
(2.4 KiB) Downloaded 2 times
by Fruitcake
Thu Jan 11, 2018 11:42 pm
Forum: Hardware
Topic: Chroma 81 - SCART and Colour interface for the ZX81
Replies: 133
Views: 8495

Re: Chroma 81 - SCART and Colour interface for the ZX81

Nice work! :D I agree with you that the first version looks better. Have you tried making the blue and green characters forming the aliens the same colour, which would give their colouring full symmetry? As requested, attached is a patched version of the game that uses the cursor keys. spaceraiders(...
by Fruitcake
Tue Jan 02, 2018 11:06 pm
Forum: Hardware
Topic: Chroma 81 - SCART and Colour interface for the ZX81
Replies: 133
Views: 8495

Re: Chroma 81 - SCART and Colour interface for the ZX81

for eee=0 to 767 seed=smsrnd(seed) dfile=peek uinteger(16396) poke dfile+$8000+eee,seed next The above code does not take into account the 'NEWLINE' positions within the attributes file. The attributes file begins with a position corresponding to the initial NEWLINE character in the display file, f...
by Fruitcake
Tue Jan 02, 2018 10:56 pm
Forum: Hardware
Topic: Chroma 81 - SCART and Colour interface for the ZX81
Replies: 133
Views: 8495

Re: Chroma 81 - SCART and Colour interface for the ZX81

Here’s some example assembler code to show the basic mechanisms for accessing the two colour modes provided by the Chroma 81 interface. CHECK AVAILABILITY Reading I/O port $7FEF can be used to check whether the Chroma colour facility is enabled: LD BC,$7FEF IN A,(C) AND $20 The A register will hold ...
by Fruitcake
Sat Dec 30, 2017 10:57 pm
Forum: Hardware
Topic: Chroma 81 - SCART and Colour interface for the ZX81
Replies: 133
Views: 8495

Re: Chroma 81 - SCART and Colour interface for the ZX81

A description of the colour modes can be found at the end of the document available from here.
by Fruitcake
Mon Nov 27, 2017 12:58 am
Forum: Emulators
Topic: New release of EightyOne available
Replies: 131
Views: 9134

Re: New release of EightyOne available

On SourceForge I collated all the versions of EightyOne (and their source) I had collected over the years and also those I could find scattered across the Internet. Although I doubted anyone would ever have a use for these very old versions, it seems a shame to lose them. However, the set is far fro...
by Fruitcake
Fri Oct 20, 2017 10:26 pm
Forum: GAMES
Topic: Monster Digger (Michael Pike, Your Computer, Dec 1984)
Replies: 0
Views: 227

Monster Digger (Michael Pike, Your Computer, Dec 1984)

Here's the game Monster Digger by Michael Pike from Your Computer magazine December 1984. A fairly simple game but quite entertaining.
by Fruitcake
Thu Oct 19, 2017 8:11 pm
Forum: GAMES
Topic: Short Circuit (David Green, Your Computer, Nov 1985)
Replies: 3
Views: 253

Short Circuit (David Green, Your Computer, Nov 1985)

Here's the game Short Circuit by David Green from Your Computer magazine November 1985. It's a version of the old favourite Tron but I thought a well polished implementation worth sharing.

I've submitted it to the Type Fantastic website and it should appear in the archive there in due course.
by Fruitcake
Tue Oct 10, 2017 10:09 pm
Forum: Hardware
Topic: ZX80 Slow mode mod
Replies: 2
Views: 289

Re: ZX80 Slow mode mod

Andy Rea wrote:
Sun Oct 01, 2017 4:23 pm
My guess would be another 74LS93
Yes it's a 74LS93! :D
ZX80_SlowModeBoard_Photo.jpg
ZX80_SlowModeBoard_Photo.jpg (91.13 KiB) Viewed 188 times
ZX80_SlowModeBoard_Schematic.jpg
ZX80_SlowModeBoard_Schematic.jpg (69.99 KiB) Viewed 188 times