Search found 408 matches

by MCes
Fri Jun 26, 2020 2:04 pm
Forum: Other Systems
Topic: Exactly how NOT to make a multicart for the C64
Replies: 113
Views: 7874

Re: Exactly how NOT to make a multicart for the C64

@Vic20-Ian from your link: "The problem usually occurs over time and can be abated by removing the memory module and cleaning the contacts." Each time that a card is removed/inserted the contacts are cleaned by the mechanical abrasion with the fiberglass exposed by the V-Cut. Nobody says t...
by MCes
Fri Jun 26, 2020 1:53 pm
Forum: Other Systems
Topic: Exactly how NOT to make a multicart for the C64
Replies: 113
Views: 7874

Re: Exactly how NOT to make a multicart for the C64

(using google translator) what sadness, first he says that HASL damages the connector of the C64 and then to prove it he says that someone has ruined... THE CARD! meaningless speeches! it is clear that he knows he is wrong but he would not say it even under torture .... He can only deceive those who...
by MCes
Thu Jun 25, 2020 7:26 am
Forum: Other Systems
Topic: Exactly how NOT to make a multicart for the C64
Replies: 113
Views: 7874

Re: Exactly how NOT to make a multicart for the C64

There is this guy in Australia selling a cart with 62 games for the C64. The cart is not gold plated (HASL) so it's a fine cartridge port destroyer (...) "HASL is dangerous for the connectors" : It's never demonstrated... The only damages that we seen in the other thread was produced, dur...
by MCes
Fri Jun 12, 2020 7:18 am
Forum: Other Systems
Topic: 8501 7501 CPU replacement
Replies: 1
Views: 598

8501 7501 CPU replacement

From the " 85MC01 " experience...... http://sleepingelephant.com/ipw-web/bulletin/bb/viewtopic.php?f=5&t=9352 the CPU replacement that use a selected 6502 N-MOS core: it manage the illegal opcodes. The CPU4C16, specific for the C16 board shape: P_20200819_192047.jpg The CPU4PLUS4, spec...
by MCes
Wed May 06, 2020 1:07 am
Forum: Other Systems
Topic: Not quite... The end of the ROM based PLA for the 64
Replies: 344
Views: 104060

Re: Not quite... The end of the ROM based PLA for the 64

We are speaking about a circuit that has to find all spikes onto 2 lines, without reasons the lines have to not change state, otherwise could be generated a problem. It implies that after the reset routine, during the test time we must note that the state does not change, so the correct output trans...
by MCes
Tue May 05, 2020 4:29 am
Forum: Other Systems
Topic: Not quite... The end of the ROM based PLA for the 64
Replies: 344
Views: 104060

Re: Not quite... The end of the ROM based PLA for the 64

I close here my possibility to help more then how I already have done, I'm reading too much nonsense concept and Also into the "lockdown" I have more interesting activities to do that write more about this.

I wrote what I wonted to tell, anybody is free to ignore (or not) my words.

Bye!
by MCes
Tue May 05, 2020 3:11 am
Forum: Other Systems
Topic: Not quite... The end of the ROM based PLA for the 64
Replies: 344
Views: 104060

Re: Not quite... The end of the ROM based PLA for the 64

If you use faster chips such as 74F, 74S or 74AHCT circuits to detect glitches then the glitches you find may not necessarily affect a C64, C128 or VIC-20 computer. So you are agree with me: if you want detect ALL possible cause of problems you have to detect all of them: 74(fast family)74 ! If you...
by MCes
Tue May 05, 2020 2:19 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

I haven't read everything, but may be that this memory map representation could help... (VIC MAP) 14-1.jpg The VIC MAP is not completely perfect, example is "COLOR" area: the 1k-nibble of colour datas are never readable by VIC on BD0..3 data bus, but they will be proposed at VIC on its VD8...
by MCes
Tue May 05, 2020 1:40 am
Forum: Other Systems
Topic: Not quite... The end of the ROM based PLA for the 64
Replies: 344
Views: 104060

Re: Not quite... The end of the ROM based PLA for the 64

Eslapion, I explicitly agree with you about chinese market, and I can note that you implicitly agree with me that 74LS279 is not a great way to find the spikes... (for time reaction, level sensed...). As you just done, I suggest to engegnerize a cartridge for spike testing with a dual D type Flip Fl...
by MCes
Mon May 04, 2020 11:43 pm
Forum: Other Systems
Topic: Not quite... The end of the ROM based PLA for the 64
Replies: 344
Views: 104060

Re: Not quite... The end of the ROM based PLA for the 64

I remembered that something about glitch sensitivity is written in an old electronic book of mine ... IMG_0001.JPG IMG_0002.JPG (this book can be also found googling "Fairchild TTL Data Book 1978", read original page number 2-18 and 2-19) it is normal that faster the gate family is, better...
by MCes
Mon May 04, 2020 7:42 am
Forum: Hardware and Tech
Topic: Blurry signal/image with ghost effects (on a 1084S)
Replies: 4
Views: 362

Re: Blurry signal/image with ghost effects (on a 1084S)

try also to put in parallel to C8 a low ESR capacitor (not less than 100uF), the type that are used for switching PSU or DC-DC converter: it could minimize the vertical issues in the last part of the left border.
by MCes
Sun May 03, 2020 12:38 am
Forum: Hardware and Tech
Topic: Faulty RAM - interpreting diag cart.
Replies: 10
Views: 819

Re: Faulty RAM - interpreting diag cart.

@Gmc
If you are using the Srowe's "dead-test" by plugging-in a rom into the diagnostic cart the RAM1 has a sense:
the standard diagnostic cartridge provide ram into RAM1.
by MCes
Thu Apr 16, 2020 2:22 am
Forum: International VIC
Topic: Una Turbo CPU?
Replies: 10
Views: 2646

Re: Una Turbo CPU?

Hey guys, if the point is "how dumping a cartridge" I already have a simple solution, it's a patched Kernal: if at startup the "commodore" key is pressed the cartridge autostart will be ignored, so you could dump it on disk (or tape), analyze it, modify it.... Take a look at the ...
by MCes
Mon Apr 13, 2020 8:50 am
Forum: International VIC
Topic: Una Turbo CPU?
Replies: 10
Views: 2646

Re: Una Turbo CPU?

Però bisogna ammettere che una cartuccia con CPU a bordo in pratica è un microcontrollore che usa il VIC come unità per le perefiche (video/audio/unità disco/cassette/porta utente ecc...), a me pare che oltre a creare un computer nuovo, diverso, si sia anche preso il peggio da ogni lato del sistema....
by MCes
Sat Apr 11, 2020 5:48 am
Forum: International VIC
Topic: Una Turbo CPU?
Replies: 10
Views: 2646

Re: Una Turbo CPU?

Ciao Orion! Anche io avevo dubbi sull'effettiva utilità di una TurboCpu su questi computer, sarebbe un virtuosismo di elettronica sperimentale, ma poco utile.... D'altronde se serve fare calcoli pesanti li possiamo fare su VICE, i nostri beneamati VIC20 hanno attualmente la potenza di calcolo di un ...