Sinclair ZX80 / ZX81 Forums

Maybe you should replace that big electrolytic capacitor by a new one .....

Siggi

There are severaöl ZX81 laptops around.
I have one, which could be seen here at Zx-Team Meeting in Mahlerts (incl. a LEGO docking station, containg a keyboard-interface card, a sound card, a ZeddyNet card and a jostick card ):
https://www.youtube.com/watch?v=P1Uo_TUB65c

Siggi

Links could alreday be found in Tom's forum:

http://forum.tlienhard.com/phpBB3/viewt ... 612#p35435

@siggi i wonder if it's possible to have a back plane that has a bi directional buffer for the data bus? The databus driver of ZX96 (old project) an Torsten's remake have a bidirectional databus driver (74LS245 or similar). But they need an enable signal (/BUSCS) generated by the card behind der bu...

the old way the force nop started at the middle ( falling edge ) of T2 however my new way, the RAMcs get de-asserted at this time but the forced nop does not start until another 1/4 cycle ( or half a 6.5mhz cycle ) The Zilog Z80a needs a 35na setup time before the rising edge of T3 when the data bu...

the old way the force nop started at the middle ( falling edge ) of T2 however my new way, the RAMcs get de-asserted at this time but the forced nop does not start until another 1/4 cycle ( or half a 6.5mhz cycle ) The Zilog Z80a needs a 35na setup time before the rising edge of T3 when the data bu...

@siggi: Excellent - are you also able to 'back up' so that instance auto-loads on each boot? Als I already wrote: CRTL is turned OFF, so I cannot go back to instance 0 to do a backup Also, could you give me a step-by-step guide so that I don't go wrong please? Enter "T" (tools) and L (load) and fol...

It works :mrgreen: I have loaded SPONZY into instance 6: Ram 16-64K, CTRL-OFF (so no USB load/save or task switching possible!), 3,25 or 6,5 Mhz. At 6,5 MHz the "Speccy" is running quite fast ;) ... Siggi Edit: @ZSOLT: The ZXMORE "Master Program" hooks into the ZX81 NMI-handler to get control again....

Is any meeting programme anywhere available? The program was posted about 30 minutes before the lectures in the meeting room on the refrigerator door. ;) Detlev and Urs: Q68/QL hardware and QL/E distribution Paul: sinclairzxworld.com Heinz: Vdrive & speech with ZX81 and Husband FORTH Matthias: Powe...

see

http://www.zx81.de/zxcms/

Siggi