Search found 699 matches

by Kakemoms
Tue Jun 25, 2019 4:29 pm
Forum: Hardware and Tech
Topic: SuperCPU for the Vic-20
Replies: 176
Views: 115322

Re: SuperCPU for the Vic-20

Ok. I don’t have any way to moderate posts to this site and moderators are generally only interested in being abusive. The site has generally become a shit throwing contest site and very few interesting things about the Vic-20 appear. You can read about the Supervixen development on mewe.com (downlo...
by Kakemoms
Wed Jun 05, 2019 10:25 pm
Forum: Other Systems
Topic: Apple-1
Replies: 4
Views: 4489

Re: Apple-1

Things are starting to get together. I have been able to get sockets and most of the ICs (only missing a few Signetics ICs). The 6502 is dated 0677 and is in plastic packaging. Since the build is a NTI board, that puts it into the correct period (many NTI boards shipped in 1977). The 6502 from Febru...
by Kakemoms
Tue Jun 04, 2019 12:57 pm
Forum: Hardware and Tech
Topic: SuperCPU for the Vic-20
Replies: 176
Views: 115322

Re: SuperCPU for the Vic-20

If you want to support character set changes in RAM and screen memory together, you would be better off with a Graphic/Memory changes queue (like using part of the joint memory to queue up memory changes), so that you don't need to copy 4Kb repeatedly to keep the screen uptodate. Also, you may want...
by Kakemoms
Sat May 25, 2019 2:04 am
Forum: Hardware and Tech
Topic: SuperCPU for the Vic-20
Replies: 176
Views: 115322

Re: SuperCPU for the Vic-20

eslapion wrote:Somehow, I suspect we're going to have a considerably faster version of Sargon II before long.
Uh oh.. ready for higher levels then? :wink:
by Kakemoms
Wed May 22, 2019 2:48 pm
Forum: Hardware and Tech
Topic: SuperCPU for the Vic-20
Replies: 176
Views: 115322

Re: SuperCPU for the Vic-20

I finally got the last ugly bug out of the MMU. Here is a short video of the following code (I start the video with a Wozmon disassembly of the code before I run it): 1FA4 78 SEI 1FA5 A2 00 LDX #$00 1FA7 A9 00 LDA #$00 1FA9 FC 22 00 NOP $0022,X 1FAC 9D 00 A0 STA $A000,X 1FAF E8 INX 1FB0 D0 F7 BNE lo...
by Kakemoms
Tue May 14, 2019 9:07 am
Forum: Hardware and Tech
Topic: SuperCPU for the Vic-20
Replies: 176
Views: 115322

Re: SuperCPU for the Vic-20

Time for another short update: I have debugged the MMU implementation for the last weeks. It is now fairly stable and IRQ is now handled as it should. Still, there are some situations with NMI and IRQ that I willl need to test (especially if they happen at the same time). Interrupt routines can now ...
by Kakemoms
Tue May 07, 2019 12:10 am
Forum: Hardware and Tech
Topic: 6561 Die Shot Reversing Explorations
Replies: 289
Views: 120465

Re: 6561 Die Shot Reversing Explorations

Ok. Thank you for the long explanation. I didn't understand that the double circles were Vcc in the first diagram (maybe I was too sleepy), and with OUT at the top instead of the bottom, it made less sense.

With the modified diagram it makes perfectly sense. :D
by Kakemoms
Sat May 04, 2019 2:25 pm
Forum: Hardware and Tech
Topic: 6561 Die Shot Reversing Explorations
Replies: 289
Views: 120465

Re: 6561 Die Shot Reversing Explorations

perhaps their first design was to make a multiple waveform device, then they converged to a more simple device, but instead of redesigning it completely they simply disconnected the unneeded parts. I recall that the 6562 datasheet mentions multiple waveforms, so it seems that they were experimentin...
by Kakemoms
Sat May 04, 2019 2:23 pm
Forum: Hardware and Tech
Topic: 6561 Die Shot Reversing Explorations
Replies: 289
Views: 120465

Re: 6561 Die Shot Reversing Explorations

Does this post from the old thread suffice? http://sleepingelephant.com/ipw-web/bulletin/bb/viewtopic.php?f=11&t=7118&p=88489&hilit=Fpga+6561#p88489 It has been a while since I wrote it, so maybe I have further thoughts now. The answer to your question is that it uses cross coupled inve...
by Kakemoms
Sat May 04, 2019 1:25 pm
Forum: Other Systems
Topic: Apple-1
Replies: 4
Views: 4489

Apple-1

Well.. I am one of those that got on the bait an bought an Apple 1. Its just a reproduction PCB, so quite "cheap" compared to the ones in museums. But it will probably take a long time to get hold of all the components.. that is components with date codes from 1976. :shock: Anyone else her...
by Kakemoms
Mon Apr 29, 2019 8:55 pm
Forum: Announcement Board
Topic: VIC-20 Software Releases of 2019
Replies: 18
Views: 29089

Re: VIC-20 Software Releases of 2019

This was posted on mewe earlier this year. Its the wozmon ported to Vic-20: wozmon6000.zip Its based on the disassembly by Jeff Tranter . If anyone here doesn't know what this is (unlikely!), its the internal machine language monitor of the Apple-I made by Steve Wozniak. Its amazingly small and effi...
by Kakemoms
Mon Apr 29, 2019 8:39 pm
Forum: Hardware and Tech
Topic: 6561 Die Shot Reversing Explorations
Replies: 289
Views: 120465

Re: 6561 Die Shot Reversing Explorations

Looks nice. :) Could you also say something about how the control register values are stored. Probably not important, but for me it would be interesting to know. And also... What are the "not used" sections of the tone generators.. Filters? Or has it something to do with the sound mixing?
by Kakemoms
Mon Apr 29, 2019 2:33 pm
Forum: Games
Topic: Bitshifter's Z-code interpreter
Replies: 39
Views: 27528

Re: Bitshifter's Z-code interpreter

Anyone knows if the Z-code interpreter source was made available?
by Kakemoms
Sat Apr 27, 2019 1:36 am
Forum: Hardware and Tech
Topic: SuperCPU for the Vic-20
Replies: 176
Views: 115322

Re: SuperCPU for the Vic-20

Some questions arise (at least for me): When executing the subroutine at $11200, what is the value of the instruction pointer? As far as i understand, the 6502 has it's original memory layout, otherwise you couldn't access screen and color ram. But how on earth can you connect the rts from this sub...
by Kakemoms
Fri Apr 26, 2019 9:29 pm
Forum: Hardware and Tech
Topic: SuperCPU for the Vic-20
Replies: 176
Views: 115322

Re: SuperCPU for the Vic-20

The latest update is basically about how to access the 1MiB external SRAM, e.g. a 6502MMU. Here is some example code: defm MMJ ; addr MMJ=Memory Management Jump byte $DC byte >/1 byte </1 endm defm MMF ; addr MMF=Memory Management Fetch byte $FC byte >/1 byte </1 endm defm LDAX ; highaddr ($ffff), a...