Search found 444 matches

by Nasta
Fri Jun 24, 2022 5:25 pm
Forum: Hardware
Topic: CPLD replacement for ZX8301
Replies: 230
Views: 51778

Re: CPLD replacement for ZX8301

What I haven't really understood: How have you read the contents of the Ula to know, what it is doing? I studied Nasta's description of the ULA. It's totally accurate and I mentioned that at my fb post. Nasta is great, respect. Thanks, I wonder if it is possible to do a few small improvements when ...
by Nasta
Fri Jun 03, 2022 8:26 pm
Forum: Hardware
Topic: Keyboard from where
Replies: 59
Views: 12573

Re: Keyboard from where

Slightly OT: Not sure who has been banned or why. Only 3 people have been banned. The most recent, on the weekend that Sir Clive passed away, was the user formerly known as "Brane_2" who was a bit of a hardware type. Apparently his hardware skills were/are lacking. (Not my observation, I'...
by Nasta
Fri Jun 03, 2022 8:25 pm
Forum: Hardware
Topic: Keyboard from where
Replies: 59
Views: 12573

Re: Keyboard from where

Deleted duplicate post
by Nasta
Thu May 26, 2022 2:46 pm
Forum: General QL Chat
Topic: Hidden MC68010?
Replies: 5
Views: 1991

Re: Hidden MC68010?

I found a thread here:
https://www.cpu-world.com/forum/viewtop ... &view=next
It seems it is indeed a custom marked 68010.
by Nasta
Tue May 03, 2022 11:43 am
Forum: Hardware
Topic: Upgrading Q40 to 68060 CPU
Replies: 72
Views: 11761

Re: Upgrading Q40 to 68060 CPU

What kind of QLiberator issues are there? Problems with MMU? I had never problems of that kind with an hyperCache 030 on the Atari. I had a look at SMSQ/E docs but couldn't find any reference to it (it is a config item). Look into it later (probably much). It probably sets up the MMU to repeat the ...
by Nasta
Thu Apr 14, 2022 2:11 pm
Forum: Software & Programming
Topic: Dhrystone benchmark QL vs Amiga
Replies: 24
Views: 5224

Re: Dhrystone benchmark QL vs Amiga

Given that the test is running on a 68060, I would expect it to be heavily cached, hence not very dependant on RAM speed...
by Nasta
Tue Mar 01, 2022 11:56 am
Forum: Hardware
Topic: Replacement for 68008
Replies: 38
Views: 7298

Re: Replacement for 68008

One thing which has not been mentioned is that running a faster CPU with it's private faster RAM and possibly other faster bus attached devices, requires a set of buffers/latches between the CPU bus and the QL bus. The faster signals the faster clocked CPU generates while accessing faster RAM etc sh...
by Nasta
Fri Feb 25, 2022 2:17 pm
Forum: Hardware
Topic: Replacement for 68008
Replies: 38
Views: 7298

Re: Replacement for 68008

Hi, Could the 68SEC000 be connected to the QL 68008 socket with an appropriate DIP to QFP adapter board, with the possibility of using it own un-contended ram? It is directly compatible when powered with 5V and the 8-bit bus width is selected. Some extra wiring is required (wiring together interrup...
by Nasta
Thu Feb 24, 2022 5:36 pm
Forum: Hardware
Topic: Replacement for 68008
Replies: 38
Views: 7298

Re: Replacement for 68008

If the cache is not enabled (and by default it's not), interrupt stack, stack frames and privileged instruction emulation have to be added for the 020 to behave like a 000/008. There are, however, several CPUs that can work like a 68008: 1) 68EC001 2) 68SEC000 3) 683xx (not all members) The latter a...
by Nasta
Sun Feb 20, 2022 6:06 pm
Forum: Hardware
Topic: Replacement for 68008
Replies: 38
Views: 7298

Re: Replacement for 68008

It is possible to run a faster 68008 variant on the QL as long as it is made to look exactly as the original 68008 at 7.5MHz. To make a long story short, the signals that need to be passed through extra logic are /DS and /DTACK. The 68008 uses both clock edges to generate various signals, If it is r...