Search found 553 matches

by tcat
Fri Sep 20, 2019 10:58 am
Forum: Hardware
Topic: 74HCxx vs 74LSxx
Replies: 17
Views: 2351

Re: 74HCxx vs 74LSxx

Hi,

As my soldering is not very neat, I am no way sure I had it functional. I run this simple test that was coded by a German ATARI branch years ago.

sfp004-test-2.JPG
Running FPU math test

This may be an indication, it hopefully works?
Thomas
by tcat
Thu Sep 19, 2019 1:11 pm
Forum: Hardware
Topic: 74HCxx vs 74LSxx
Replies: 17
Views: 2351

Re: 74HCxx vs 74LSxx

Hi, I have only a simple `pistol' soldering iron, and I am not very skilfull with it. This is what I have, ICs populated in the sockets, VCC/GND sourced around PSU connector. GEM-BENCH reports some 1400% on FPU math test, while SYSINFO reports NO-COPROCESSOR fitted. What does it actually mean? Many ...
by tcat
Mon Sep 09, 2019 11:22 am
Forum: Hardware
Topic: 74HCxx vs 74LSxx
Replies: 17
Views: 2351

Re: 74HCxx vs 74LSxx

Hi, No idea it will work in the end, but this is how it may fit inside my STFM machine. P1 should connect to CPU pins using ribbons, at least that is the idea so far, but there is RP7 red component getting in the way on one CPU side!!! Inevitably the ribbon will partly cover CPU from top, any precau...
by tcat
Sat Aug 17, 2019 5:14 pm
Forum: QL Emulation
Topic: uQLx 2018a
Replies: 25
Views: 4110

Re: uQLx 2018a

Hi, Still thinking about zoom>1, this is when the emulator window does not get updated properly. On my further looking into, with zero X-Windows knowledge, this is what I see happening. In `xql.c', `x.c' there is XposeEvent, looks like an event loop, from within `redraw-screen()' is called. In `redr...
by tcat
Fri Aug 16, 2019 12:42 pm
Forum: Hardware
Topic: 74HCxx vs 74LSxx
Replies: 17
Views: 2351

Re: 74HCxx vs 74LSxx

Hi, Just spotted the application note `AN947', pointed a few posts above, is missing appendices B,C. Anyone having the full document? EDIT The document I have is `AN947_REV0.PDF', I guess REV0 stands for revision 0. It just happens to miss some pages at the end, containing appendices B,C. It is Moto...
by tcat
Fri Aug 16, 2019 8:40 am
Forum: Hardware
Topic: MAB 8049H P A038 comapible?
Replies: 10
Views: 770

Re: MAB 8049H P A038 comapible?

Hi, I have thought, Intel's 8048, 8049 are single chip microcontrollers, having program and data memory. And can be user programmed simillarly as more modern PIC micros. I believed program resides in internal EPROM. As that what HERMES is all about, is just a new firmware for IPC (8049)? Apologies, ...
by tcat
Tue Aug 13, 2019 5:30 pm
Forum: Hardware
Topic: Issue 8 discussions...
Replies: 125
Views: 12189

Re: Issue 8 discussions...

Hi,

Rereading the topic now and again. I wish to ask, what makes it different to hook 8302 on CPU data bus as with Iss#6 vs RAM bus in Iss#5, is there any performance gain?

Many thanks
Tomas
by tcat
Tue Aug 13, 2019 12:32 pm
Forum: Hardware
Topic: 74HCxx vs 74LSxx
Replies: 17
Views: 2351

Re: 74HCxx vs 74LSxx

Hi Nasta, Thank you for explaining, re `power decoupling and grounding', I tried to put a capacitor close to VCC of each chip. Power comes through P2 connector, which should connect to common +5V rail inside ST machine (have no idea yet where best to source, seeking advice), connector P1 should inte...
by tcat
Tue Aug 13, 2019 8:38 am
Forum: Hardware
Topic: 74HCxx vs 74LSxx
Replies: 17
Views: 2351

Re: 74HCxx vs 74LSxx

Hi Derek,

Ah, `plating rivets', then. Looked for them on the net, they sell in a thousand pack, I have counted I just need 33 holes to plate through, standard 0.8mm drill, these are on the PCB front. The rest of PLCC68 holes are routed on the rear, no plating needed.

Thank you
Tomas
by tcat
Mon Aug 12, 2019 10:02 am
Forum: Hardware
Topic: 74HCxx vs 74LSxx
Replies: 17
Views: 2351

Re: 74HCxx vs 74LSxx

Hi, An old topic, I know. I've had some time and designed a PCB prototype based on the schematics above. As I have no SMD skills, I just stick to standard TTL in DIP sockets. Exception being PLCC68 for the FPU. I tried to make the board as small as possible, and this is best I can do at the moment. ...