Search found 33 matches

by Richardc64
Thu Aug 18, 2022 8:11 am
Forum: Hardware and Tech
Topic: A strictly cosmetic mod
Replies: 3
Views: 668

A strictly cosmetic mod

...for now. More functional modifications are in the design phase.
PICT0591.jpg
PICT0598.jpg
by Richardc64
Sat Jul 18, 2020 5:53 pm
Forum: Hardware and Tech
Topic: Trouble getting White characters
Replies: 9
Views: 585

Re: Trouble getting White characters

Correct, eslapion, 2 alone works, shifted gives quote, and CTRL-9 and -0 turn RVS on & off.
eslapion wrote: If all the above is true then there may be a problem with the BASIC ROM.
Luck is not with me for this possibility, either: Only the Kernal ROM is socketed.
by Richardc64
Sat Jul 18, 2020 12:42 pm
Forum: Hardware and Tech
Topic: Trouble getting White characters
Replies: 9
Views: 585

Re: Trouble getting White characters

Just my luck it would be the VIA that isn't socketed. Reverse E doesn't appear. That key combination has no effect at all. When you do something like PRINT "{ctrl}+2" does it show a reverse E, but just not change the color to white? Or does the reverse E fail to appear? You're getting whit...
by Richardc64
Fri Jul 17, 2020 8:23 pm
Forum: Hardware and Tech
Topic: Trouble getting White characters
Replies: 9
Views: 585

Re: Trouble getting White characters

groepaz wrote: Fri Jul 17, 2020 11:44 am Are you sure the CTRL key works at all?
Every color key works with CTRL except White (2).
by Richardc64
Fri Jul 17, 2020 11:22 am
Forum: Hardware and Tech
Topic: Trouble getting White characters
Replies: 9
Views: 585

Trouble getting White characters

Keyboard CTRL2 or PRINT "[CTRL2]" doesn't change character color: it stays what it was previously.

I can get white chrs by POKEing color RAM or location 646, but by keyboard or by PRINT doesn't produce White chars.

Has anyone seen this or know of a fix?
by Richardc64
Sat Jan 25, 2020 8:39 pm
Forum: Hardware and Tech
Topic: Any thoughts on this video mod?
Replies: 12
Views: 3572

Re: Any thoughts on this video mod?

... if you're hooking up to a flatscreen (composite is terrible in that arena) but I wouldn't hold my breath. I don't understand why that should be. My VCR (Yeah, I still have and use one,) output is composite and it has always looked fine on flat screen TVs. I've only recently connected VIC to a f...
by Richardc64
Sun Dec 15, 2019 2:38 pm
Forum: Hardware and Tech
Topic: Soliciting VIC-20 Internal memory expansion ideas
Replies: 61
Views: 7720

Re: Soliciting VIC-20 Internal memory expansion ideas

I cited the C64 mechanism only as an example of a register that can't get banked out, regardless of where it might be located or the configuration it sets up.

(Obviously, my edit for "clarity" was lacking.)
by Richardc64
Sun Dec 15, 2019 10:49 am
Forum: Hardware and Tech
Topic: Soliciting VIC-20 Internal memory expansion ideas
Replies: 61
Views: 7720

Re: Soliciting VIC-20 Internal memory expansion ideas

My personal goal is to allow all the memory to be RAM, like on the C64... Jim To bank ALL memory of a 64K range the banking has to be done from a location that does not and cannot get banked. The C64 accomplishes this with a 6-bit I/O port at locations 0000h and 0001h on the 6510 mpu. To add decodi...
by Richardc64
Sun Nov 03, 2019 5:20 pm
Forum: Other Systems
Topic: SaRuMan-64 C64/C64c 64k static RAM for DRAM replacement board
Replies: 20
Views: 8139

Re: SaRuMan-64 C64/C64c 64k static RAM for DRAM replacement board

Where do you tap the signals to effectively disable them? The /RAMCASs are at R29 and R30. I'm not certain about the /RAS resistor: It looks like R7 in the flat schematic and R1 in the 'D. All three Rs are 68ohm. R29 and R30 are near the DRAMs and I expect the /RAS resistor is nearby. I'll have to ...
by Richardc64
Sun Nov 03, 2019 9:45 am
Forum: Other Systems
Topic: SaRuMan-64 C64/C64c 64k static RAM for DRAM replacement board
Replies: 20
Views: 8139

Re: SaRuMan-64 C64/C64c 64k static RAM for DRAM replacement board

Very Cool! This motivates me to try something I've thought about for a while: to do something similar on the C128. I wouldn't de-solder the sixteen 64Kx1s in the flat model or even the four 64Kx4s in the 'D, though, but instead disable them by making their /RAS and /CAS high.
by Richardc64
Mon May 20, 2019 10:46 am
Forum: Hardware and Tech
Topic: Substituting 65C22 for VIC's VIAs
Replies: 3
Views: 3072

Re: Substituting 65C22 for VIC's VIAs

Thank you. That was very informative. Doesn't solve the mystery of which socket my long-lost-friend's 65C22 worked in and which it didn't, but since the chip I have isn't WD I don't think I'll try it in either VIA socket.

Thanks again
by Richardc64
Sun May 19, 2019 4:26 pm
Forum: Hardware and Tech
Topic: Substituting 65C22 for VIC's VIAs
Replies: 3
Views: 3072

Substituting 65C22 for VIC's VIAs

Years ago an internet friend told me he substituted a 65C22 for one of the VIC's VIAs and said it worked in one socket but not in the other. I don't remember which socket he said was the one that caused problems, and after all this time doubt if he would remember either, even if I knew how to contac...
by Richardc64
Fri May 06, 2016 9:27 pm
Forum: Programming
Topic: Writes to $9010-$901F
Replies: 5
Views: 2800

Re: Writes to $9010-$901F

Thanks for the mention. I got a little carried away decoding that area. It could've been done much simpler, but I was planning ahead, in case I might think of other items to put in that area. (I have, but that discussion would be more suited to the Hardware subforum.) Anyway, it seemed a waste to ha...
by Richardc64
Sat Jan 09, 2016 7:10 am
Forum: Hardware and Tech
Topic: Thinking of a SuperCPU VIC
Replies: 115
Views: 19445

Re: Thinking of a SuperCPU VIC

To very briefly thread-jack... I have an MD65SC22 (Mitel) salvaged from something years ago. Can I safely use it in a VIC-20, or is it likely to have the IRQ problem mentioned? Also years ago, someone told me tried a CMOS '22 in his VIC and it worked in one VIA socket but not in the other, but I've ...
by Richardc64
Tue Nov 03, 2015 9:14 am
Forum: Hardware and Tech
Topic: UltiMem
Replies: 201
Views: 38178

Re: UltiMem

Cool! I blame my eyesight for missing that. (That and me looking for it among the BLK registers.)