Search found 1065 matches

by groepaz
Mon Apr 23, 2018 5:15 pm
Forum: General Topics
Topic: I got a Commodore Vic-20
Replies: 20
Views: 10547

Re: I got a Commodore Vic-20

US Army trained and was dealing with electronics before most of us were born.
that doesnt make this circuit any better really :) no doubt he has published some good stuff - but there is no doubt some of the things he made are a bit questionable either.
by groepaz
Mon Apr 23, 2018 10:56 am
Forum: General Topics
Topic: I got a Commodore Vic-20
Replies: 20
Views: 10547

Re: I got a Commodore Vic-20

ah modern circuit should have a crowbar circuit to prevent overvoltage on failure... even THAT can not be fast enough in some situations, but a relay certainly isnt. a relay based circuit can only ever protect against overvoltage which raises relatively slow while the PSU is being used - however the...
by groepaz
Sun Apr 22, 2018 2:07 pm
Forum: Emulation and Cross Development
Topic: UDGs on 8 Kb+ expanded
Replies: 12
Views: 7648

Re: UDGs on 8 Kb+ expanded

conio is optimized portable console output, so it doesnt understand any of the petscii control codes... if you want that, use stdio functions, putchar() would be the function that can do it. that said, its probably a better idea to write to the respective VIC registers directly (someone else can pro...
by groepaz
Sat Apr 21, 2018 3:57 pm
Forum: Hardware and Tech
Topic: VIA 1 CA2 behaviour when switching from output to input
Replies: 10
Views: 4833

Re: VIA 1 CA2 behaviour when switching from output to input

indeed it is. there should be a separate test program just for this =P
by groepaz
Sat Apr 21, 2018 3:24 pm
Forum: Hardware and Tech
Topic: VIA 1 CA2 behaviour when switching from output to input
Replies: 10
Views: 4833

Re: VIA 1 CA2 behaviour when switching from output to input

i guess we really need 1541 versions of those tests :) (ie its not really a VIA emulation thing - its a VIC20 specific thing here)
by groepaz
Thu Apr 19, 2018 1:44 pm
Forum: Hardware and Tech
Topic: Mega-Cart
Replies: 695
Views: 186967

Re: Mega-Cart

he just had is regular outburst and ragequit over some silly argument on IRC. he'll be back in a year or so. its not the first time this happened :)
by groepaz
Tue Apr 17, 2018 8:49 am
Forum: General Topics
Topic: I got a Commodore Vic-20
Replies: 20
Views: 10547

Re: I got a Commodore Vic-20

is that Sav64 the placebo thing that will safely cut the power with a relay.... a couple hundred microseconds after the C64 was fried? that said, yeah, dont use the old PSUs. dont use those silly "saver" circuits either. a plain simply new modern PSU will do the trick (even more so for the...
by groepaz
Wed Apr 04, 2018 11:35 am
Forum: General Topics
Topic: ** Revision 2018 Invitation / Website
Replies: 11
Views: 5694

Re: ** Revision 2018 Invitation / Website

as usual, managed to miss most ppl i was looking for =P
by groepaz
Wed Apr 04, 2018 11:31 am
Forum: Programming
Topic: Amen brother ~ 6 bit audio @ 16.3kHz
Replies: 34
Views: 6711

Re: Amen brother ~ 6 bit audio @ 16.3kHz

what funky assembler is that? :)
by groepaz
Tue Mar 20, 2018 12:29 pm
Forum: Emulation and Cross Development
Topic: x86 -> 6502 reassembler
Replies: 2
Views: 4519

Re: x86 -> 6502 reassembler

in most non trivial code all the fancy optimizations will get lost in the x86->6502 translation and you'll end up with code similar to what cc65 produces
by groepaz
Mon Mar 12, 2018 9:51 pm
Forum: Other Systems
Topic: Plus/4 joystick adapter
Replies: 13
Views: 9178

Re: Plus/4 joystick adapter

perhaps even try higher values... you shouldnt need much current (almost none) afterall

and yes 15 years ago it was easy to get deals like that... i wish i had got myself a stack of plus4 and vic20 too.... i only got a dozen C64s and drives :)
by groepaz
Mon Mar 12, 2018 7:24 pm
Forum: Hardware and Tech
Topic: RAM expansion cross-talk issues (split from: Bitshifter's Z-code interpreter)
Replies: 51
Views: 14062

Re: RAM expansion cross-talk issues

you cant rely on those testers, not seldomly oldish chips work fine in a tester that only puts very slow signals on a chip, but on a mhz or two it fails
by groepaz
Mon Mar 12, 2018 7:19 pm
Forum: Other Systems
Topic: Plus/4 joystick adapter
Replies: 13
Views: 9178

Re: Plus/4 joystick adapter

i'd perhaps even use 470Ohm - but looks OK to me
by groepaz
Tue Mar 06, 2018 7:34 pm
Forum: Hardware and Tech
Topic: Need RAM test utility
Replies: 14
Views: 4456

Re: Need RAM test utility

You do not have the required permissions to view the files attached to this post.
wut?

(mod: that happens with *all* attachments done in postings in the 'General Topic' sections. For whatever reason. Remedied by moving the thread into the Hardware section, where it belongs anyhow ...)