| Author |
Message |
Forum: Hardware Topic: Blue... wait, is it April again already? |
| Paganini |
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Posted: Thu May 02, 2024 5:43 pm
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Replies: 24
Views: 663
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| ... reasons you just mentioned, and also for the speed / ease of construction. In other news, I did some basic testing of my ACIAs. The "Rockwell" ones all seem fine, except that two of them lost pins when I pulled them back out of the breadboard. The "CMD" ones are at ... |
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Forum: General Discussions Topic: 65xx parts sources, genuine and fake |
| Paganini |
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Posted: Tue Apr 30, 2024 10:15 pm
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Replies: 174
Views: 195486
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| ... UTSource is a supplier I and other forum members have had reasonably good luck ordering from in the past. This particular time I ordered some Rockwell 65C51s and some CMD G65SC51s. These, like other chips I've ordered in the past, are supposed to be used working pulls but in good condition. ... |
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Forum: Programming Topic: No love for FORTRAN? |
| Dr Jefyll |
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Posted: Tue Apr 23, 2024 4:20 pm
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Replies: 42
Views: 6652
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| ... existing NMOS project (especially a home-built). You'd be better off with an older 'C02 if you can find one, such as those made in days of yore by Rockwell, CMD and others. To be clear, many hobbyists have used the WDC chip and had no trouble. But the older devices have much gentler rise and fall ... |
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Forum: Newbies Topic: Build 6502 with TTL components |
| ttlworks |
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Posted: Mon Apr 15, 2024 7:30 am
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Replies: 25
Views: 21410
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| ... NMOS designers", long story). 65C02 has STZ instruction, while NMOS 6502 has not. BCG (Bitwise constant generator) is support for the Rockwell R65C02 Bit testing/manipulation instructions (NMOS 6502 and non_Rockwell 65C02 lack them). c74_block_extra.png |
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Forum: Newbies Topic: 6502 From the beginning |
| drogon |
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Posted: Sat Apr 06, 2024 2:47 pm
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Replies: 43
Views: 28397
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| ... to see what would happen but to my surprise - nothing. It just stopped then started again. This is just one data point and it was a slightly newer Rockwell 6507, so who knows. -Gordon |
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Forum: Newbies Topic: 6502 From the beginning |
| rob42 |
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Posted: Tue Apr 02, 2024 9:21 pm
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Replies: 43
Views: 28397
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| ... on the topic of 'bootstrapping'. Thank you so much, Bill, for this and the welcome. --- According to information I have, 2000 was the last year Rockwell produced any 6502-family chips. That R6502BP is indeed a fake. You should be aware that the 65C02 is a commonly-counterfeited part that regularly ... |
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Forum: Newbies Topic: 6502 From the beginning |
| BigDumbDinosaur |
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Posted: Tue Apr 02, 2024 4:33 pm
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Replies: 43
Views: 28397
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| ... the bottom left is light, which is what I'd expect from an indentation being lit from the top right. I'm pretty sure that wasn't happening when Rockwell were making 6502s. I noticed that as well. The markings are wrong for a genuine Rockwell part, and I have never seen the real McCoy with laser ... |
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Forum: Newbies Topic: 6502 From the beginning |
| BigDumbDinosaur |
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Posted: Tue Apr 02, 2024 4:12 pm
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Replies: 43
Views: 28397
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| Welcome, Rob! To be clear, I have a Rockwell R6502BP, which I understand to be a 3MHz (as denoted by the 'B') NMOS(?) CPU with a 2008 date code. That's a fake. See our sticky topic, " 65xx parts sources, genuine and fake ." The ... |
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Forum: Newbies Topic: 6502 From the beginning |
| John West |
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Posted: Tue Apr 02, 2024 12:53 pm
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Replies: 43
Views: 28397
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| ... the bottom left is light, which is what I'd expect from an indentation being lit from the top right. I'm pretty sure that wasn't happening when Rockwell were making 6502s. |
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Forum: Newbies Topic: 6502 From the beginning |
| GARTHWILSON |
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Posted: Tue Apr 02, 2024 9:32 am
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Replies: 43
Views: 28397
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| To be clear, I have a Rockwell R6502BP, which I understand to be a 3MHz (as denoted by the 'B') NMOS(?) CPU with a 2008 date code. That's a fake. See our sticky topic, " 65xx parts sources, genuine and fake ." The R prefix ... |
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Forum: Newbies Topic: 6502 From the beginning |
| rob42 |
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Posted: Tue Apr 02, 2024 8:44 am
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Replies: 43
Views: 28397
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| ... and building my own circuits, in my own way, then, when they don't work, figuring out why they don't work and finding a fix. To be clear, I have a Rockwell R6502BP, which I understand to be a 3MHz (as denoted by the 'B') NMOS(?) CPU with a 2008 date code. The way I have things right now, I can ... |
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Forum: Programming Topic: “IMPROVED” MOTOROLA S-RECORD LOADER |
| BigDumbDinosaur |
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Posted: Sun Mar 24, 2024 2:50 pm
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Replies: 4
Views: 2806
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| ... file types (the others are Intel hex and raw binary). As originally developed by Mike Kowalski, the assembler understands the NMOS 6502 and Rockwell 65C02 instruction sets. Since these MPUs have a 16-bit address bus, the original assembler generates one or more S1 (data) records, and one ... |
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Forum: Hardware Topic: Connecting a 16-key keypad to VIA: Did I do it right? |
| GARTHWILSON |
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Posted: Mon Mar 18, 2024 10:45 pm
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Replies: 21
Views: 3710
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| ... true CMOS inputs; so when there's no connection through any button being pushed, then yes, you'll need a resistor to pull the input up or down. Rockwell's and other brands' CMOS VIAs' inputs are not high-impedance, and are really more like and LSTTL input which would require a very heavy resistive ... |
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Forum: Hardware Topic: R6520_M6821 running at low freq. |
| drogon |
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Posted: Mon Mar 18, 2024 2:57 pm
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Replies: 5
Views: 2436
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| ... than it just stopping when the wire was unplugged for a couple of seconds the thing just kept on running as if nothing had happened. These were Rockwell 6507s if that makes a difference... I never tried it for more than a few seconds but it was mildly amusing at the time. -Gordon |
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Forum: General Discussions Topic: Modifying Micromon to run on Planck6502 |
| SamCoVT |
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Posted: Tue Mar 12, 2024 1:50 pm
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Replies: 7
Views: 2380
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| ... I use RTS/CTS handshaking on my board (I've built three of them now) and it's been rock-solid at 38400bps (using an overclocked (3.6864MHz) Rockwell R65C51) with no interchar delays, no line-ending delays, and with either a 4MHz or 7.3728MHz system clock. If your handshaking is working properly, ... |
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