Sinclair ZX80 / ZX81 / Z88 Forums

My guess is they are using the logic to detect a certain address in the ROM, and changing a few bits on the data bus to write a new opcode out on the bus, thus changing one single instruction. Very clever fix. I guess since the ROMS are special custom chips, not just EEPROMS, it was too expensive t...

That page doesn't quite add up to me... The description describes extra ROM piggybacked on top of the original ROM. However, the picture shows a couple of 74LS logic chips (A triple 3 input NOR and a triple 3 input NAND) on top of the Z80 with no extra ROM in sight. Looks more like someone screwed u...

yerzmyey wrote:I wonder why the file http://www.user.dccnet.com/wrigter/inde ... es/BMP2P.P You pointed doesn't work with EughtyOne emularor...

Because you haven't enabled WRX graphics in the Hardware dialog box...

Mike

I'm having a problem with loading .p or .o files. Once I select them, it should automatically LOAD "", but it doesn't. In previous uses of Eighty-One, I never had a problem with it. Now I do. Is this an error? You can turn on/off auto loading of files by opening the Tape Manager (Options->Tape Mana...

Ah, SP81.

That's stored on a hard drive from a PC that's long died. I'll dig it out sometime and put it on the web for you.

Mike

If you're looking for a clock accurate emulation of the Z80 in software, maybe the best place to start would be something like the VHDL source for T80?

http://www.opencores.org/projects.cgi/web/t80/overview

Mike

Speed and sound emulation are linked. I think the speed issue is due to the inaccurate timer I'm using - once I've rewritten the sound code, the timing will then depend on the accuracy of how fast DirectSound empties it's buffer (Hopefully, 44.1khz is really 44.1khz etc) and the speed will be more a...

eighty-one: ql emulation never starts, load from audio source doesn't work yet, support of .p and .o files?, speed? everything is too slow, even loading from a wav file takes longer than what it would take on a real ts2068. support of TS2068 joystick is really needed for some joystick-only programs...

I haven't got a copy, but around 15 years ago I borrowed it from my local library and kept it for 6 months... The Adventure system in the book does work. There are a number of adventures written with it - the only name I can think of atm is "greedy gulch". Oh, hang on a min... all the adventures on ...

The interesting thing about the ARTIC adventures, is if you look at them in a hex editor all the text is in ASCII not ZX81 character set. They must have been ported from another system...

Mike