Search found 40 matches

by steve
03 Oct 2020, 22:28
Forum: Hardware and software hacking
Topic: microtron
Replies: 42
Views: 7961

Re: microtron

Regarding Aux Out utilization a solution keeping 3 bits of resolution for the Audio and 256 VGA colors (with the fully separated H and V Syncs) is to reuse the SPI lines also for Leds (keeping SS high as a switch-on led, while the other 2 are fully controllable). The leds will blink in case of SPI d...
by steve
11 Sep 2020, 19:36
Forum: Hardware and software hacking
Topic: microtron
Replies: 42
Views: 7961

Microtron schema update

Hoping that the "pull to register" is a viable solution, I did some more simplification on the overall circuit. This changes together with the other things discussed previously are depicted in the overall schema below: schema2.jpg Now is really Super Micro! :) Summary of changes: 1. Removal of W reg...
by steve
08 Sep 2020, 20:33
Forum: Hardware and software hacking
Topic: microtron
Replies: 42
Views: 7961

LUT optimized registry wiring explained

The "LUT optimized" wiring of TUVW registers is the most peculiar part of the microtron proposal and seemed to me difficult to be digested. With this post I will try to explain it with some more details hoping to make the overall architecture more clear. Let's start describing the function of each r...
by steve
05 Sep 2020, 20:45
Forum: Hardware and software hacking
Topic: microtron
Replies: 42
Views: 7961

Pull to a register

Willing just to have a confirmation from the electronics savvy of you regarding the possibility to pull to a register and not just up or down. This is the standard pull-up and pull-down: ELECPullUpResistor.jpg I would just rotate one picture to make more clear the configuration I want to comment: EL...
by steve
02 Sep 2020, 21:29
Forum: Hardware and software hacking
Topic: microtron
Replies: 42
Views: 7961

Re: microtron

For information, I've found a place where the ROM code page change happens: 02fc 0200 nop 02fd 0200 nop 02fe 0200 nop ENTER: 02ff fc03 bra .next2 1465 bra('.next2') #0 Enter at '.next2' (so no startup overhead) NEXTY: 0300 1517 ld [$17],y 1469 ld([vPC+1],Y) #1 NEXT: 0301 8115 adda [$15] 1474 adda([v...
by steve
01 Sep 2020, 17:16
Forum: Hardware and software hacking
Topic: microtron
Replies: 42
Views: 7961

Re: microtron

Regarding size, I was not referring to physical board space (and by chance I've seen back your very nice replacement to which I've given my star a long time ago), but chips count. 10 chips out of 38 is a relevant percentage in gigatron, but in the case of microtron I'm trying to stay around the 20 c...
by steve
30 Aug 2020, 21:30
Forum: Hardware and software hacking
Topic: microtron
Replies: 42
Views: 7961

Re: microtron

Ciao Ken! Regarding the Roelh ALU I was referring to the one depicted on the page I was pointing out that was seemingly using 8x 74153 and 2x 7486. My worry was about the ripple carry delay. But you're right, this version is not suitable since it's also missing the required subtraction. The Gigatron...
by steve
29 Aug 2020, 20:55
Forum: Hardware and software hacking
Topic: microtron
Replies: 42
Views: 7961

Re: microtron

PPS another thing I've found reading old posts is this one: https://hackaday.io/project/160506-4-bit-ttl-alu/log/151031-the-multiplexer-is-the-heart-of-the-alu Is a 10 chip "mammoth" and so still not really fitting into the microtron, but if it would be fast enough in case of gigatron this version w...
by steve
29 Aug 2020, 12:04
Forum: Hardware and software hacking
Topic: microtron
Replies: 42
Views: 7961

Re: microtron

PS I was by chance reading trough the very interesting post on high resolution and seems that the 7 bits per color change was already been spot and took into consideration by Marcel for various use: But we don't have enough bits for two independent 4-bit RGBI pixels. So we need a trick. Many monitor...
by steve
29 Aug 2020, 11:00
Forum: Hardware and software hacking
Topic: microtron
Replies: 42
Views: 7961

Re: microtron

You're aiming for the Microtron to be mostly SMD right? My preference would be to go for things in the JCLPCB(or similar) parts list so people could get something with all the fiddly bits done. I'm guessing you're against the idea of doing a layout with 161 chips really close together and then stic...