Search found 133 matches

by Pr0f
Mon Jan 15, 2018 1:59 pm
Forum: Compatibles Corner
Topic: a DIY home build project...
Replies: 37
Views: 1572

Re: a DIY home build project...

There is code available for download to the propeller that emulates ay8910, Commodore SID chip and a WAV player, so more interesting sound options are there, a driver would be required to push the data down to the propeller, but using an 8 bit fast serial link running at 1M, you can shift a lot of d...
by Pr0f
Fri Jan 12, 2018 7:22 am
Forum: General QL Chat
Topic: Why did Sinclair hate National Semiconductor?
Replies: 4
Views: 294

Re: Why did Sinclair hate National Semiconductor?

I wonder if it was a loading issue, or maybe slew rate ?

Without comparing the data sheets for NAT semi and maybe TI or whoever else also made the LS series of logic, it's hard to say.
by Pr0f
Thu Jan 11, 2018 9:04 pm
Forum: Compatibles Corner
Topic: a DIY home build project...
Replies: 37
Views: 1572

Re: a DIY home build project...

This is the one: https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjYtKnP5dDYAhUJIcAKHXcCCfoQFggoMAA&url=https%3A%2F%2Fwww.nxp.com%2Fdocs%2Fen%2Fdata-sheet%2FSC26C92.pdf&usg=AOvVaw1vCoiVRHgau38D-llqEBoh It has some dis...
by Pr0f
Thu Jan 11, 2018 11:34 am
Forum: Compatibles Corner
Topic: a DIY home build project...
Replies: 37
Views: 1572

Re: a DIY home build project...

I am using a 68901, which could and probably will.eventually go in the fpga with video, the reason for using the separate chip to start with is ease of testing. This acts as interrupt controller for the QL, totally replacing the zx8302. It has a serial controller on board, 4 timers, and 8 programmab...
by Pr0f
Thu Jan 11, 2018 11:20 am
Forum: Software & Programming
Topic: ROMable SMSQ/E
Replies: 28
Views: 959

Re: ROMable SMSQ/E

Something could emulate a gold card or super gold card, then in theory that version of SMSQ/E should work.

It's purely speculation.
by Pr0f
Thu Jan 11, 2018 11:15 am
Forum: General QL Chat
Topic: QL 34th Anniversary new hardware.
Replies: 30
Views: 1304

Re: QL 34th Anniversary new hardware.

Happy birthday Dave, and a Minerva carrier might be useful... I will order on the 14th Feb
by Pr0f
Wed Jan 10, 2018 9:51 pm
Forum: Software & Programming
Topic: ROMable SMSQ/E
Replies: 28
Views: 959

Re: ROMable SMSQ/E

you say it wastes either ROM or RAM, but it's probably cheaper - if you are going to implement a large amount of RAM in a system it will probably be DRAM on a simm, and if its on a 68020 or better processor - it will be 32 bits wide - such RAM is relatively cheap and reasonably fast. ROM isn't cheap...
by Pr0f
Wed Jan 10, 2018 9:23 pm
Forum: Software & Programming
Topic: ROMable SMSQ/E
Replies: 28
Views: 959

Re: ROMable SMSQ/E

... On a newly designed system, you probably want to start from ROM and run there, without runtime relocation. Tobias Unless of course your RAM is 32 bits wide and your ROM is 8 or 16 bits - then you want to be running code out of the RAM, and suffer the relatively small copy overhead. In a 68030 s...
by Pr0f
Wed Jan 10, 2018 9:12 pm
Forum: Software & Programming
Topic: ROMable SMSQ/E
Replies: 28
Views: 959

Re: ROMable SMSQ/E

There are some tricks there that can be played - the FC lines from the CPU tell you what sort of access is being made - if memory serves me right, the first 2 vectors differ from the others in the FC code they use. That means that these vectors could be provided by a logic gate to go point to some o...
by Pr0f
Wed Jan 10, 2018 8:58 pm
Forum: Software & Programming
Topic: ROMable SMSQ/E
Replies: 28
Views: 959

Re: ROMable SMSQ/E

Are there any restrictions about where in memory it must go (other than the initial 2 vectors must be in ROM of some sort to point to it)?

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