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by Silverlock
Wed Sep 02, 2020 1:59 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Old Meets New
Replies: 59
Views: 9059

Re: Old Meets New

EPROMs which contain the operating firmware of EPROM program Silverlock's EPROM reading version sounds like it is already fully formed for that purpose, so maybe you wouldn't mind attaching it here, Silverlock? Up to you of course, it's your sketch. Not at all; I'm just a little flabbergasted that ...
by Silverlock
Sat Aug 29, 2020 8:29 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Old Meets New
Replies: 59
Views: 9059

Re: Old Meets New

Mentioning eprom programmers, my little connundrum..... The eprom programmer I built many years ago has an eprom in it but I don't think I've got a copy of that eprom - and of course I can't use my programmer to copy or read it. After I dup'd the two monitor EPROMs, I hooked the duplicates up to an...
by Silverlock
Sat Aug 29, 2020 3:11 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Old Meets New
Replies: 59
Views: 9059

Re: Old Meets New

The mod I made to the single step circuitry seems to have gotten the trainer to power up reliably. I wired in a little buck boost converter to the 26V line and was able make duplicates of the old monitor EPROMs. I then swapped the dups in, erased the old EPROMs, re-programmed them and put them back ...
by Silverlock
Sun Aug 23, 2020 4:40 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Old Meets New
Replies: 59
Views: 9059

Re: Old Meets New

Yep, that's the book. I hate to imagine what it would cost in today's money, it wasn't uncommon for technical books to cost £40+ in the 1980s Mine says $14.50 on the back. That'd be in US$ I imagine. Googling exchange rates in 1985, that translates to about $20 Canadian and about £11. 2020 me think...
by Silverlock
Sun Aug 23, 2020 3:41 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Old Meets New
Replies: 59
Views: 9059

Re: Old Meets New

Is the power-on-reset circuitry applying the just S100 reset or also utilising the POS line which needs 10ms? Just /PRESET (pin 75). /POC (pin 98) isn't used in this beastie. No paging, no banking, and the first 4 locations are hardwired to 0xC3, 0x00, 0xF0, 0xF0: a jump to the monitor in EPROM. I ...
by Silverlock
Sun Aug 23, 2020 2:13 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Old Meets New
Replies: 59
Views: 9059

Re: Old Meets New

Patched! A D type flip flop had its output hooked up to the async load input of a 4 bit counter. The D input was hardwired to high, and the output would only go low (loading the 4 bit counter with 0) when the output of the counter got to 4 (at which time it asserted /NMI). I knew there was a glitch ...
by Silverlock
Sun Aug 23, 2020 12:21 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Old Meets New
Replies: 59
Views: 9059

Re: Old Meets New

Progress. The monitor board/front panel uses a standard "assert /NMI after N /M1 cycles" method of single stepping the Z80. The problem appears to be that at power up there's a glitch on that signal being sent to the CPU card. So as soon as it does start up it sees an NMI request, tries to store the...
by Silverlock
Sat Aug 22, 2020 6:49 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Old Meets New
Replies: 59
Views: 9059

Re: Old Meets New

scruss wrote: That's rather lovely. If you're still in the GTA, Josh Bensadon in Richmond Hill is a master at S100 tracing/fixing.
I grew up about 13 km north of Richmond Hill but I'm a few provinces away from there nowadays. I'm just going to have to head down to the basement and see if I can't figure it out.
by Silverlock
Sat Aug 22, 2020 6:34 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Old Meets New
Replies: 59
Views: 9059

Re: Old Meets New

Strange one that. Assuming reset is active low, it's as though the reset input or reset circuit needs to see a falling edge before the rising edge, which will only happen if the power is on first (and reset not asserted) before it is then pressed and released. The Z80 reset line is active low, and ...
by Silverlock
Thu Aug 20, 2020 10:32 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Old Meets New
Replies: 59
Views: 9059

Re: Old Meets New

Not a bad start. :) If you have the means to do so you should maybe read and save backups of the code in the EPROMs, as they are probably getting to the age where bit-rot (data fade) could begin to be a problem. I have a couple of handfuls of 2716s in my parts box, and the onboard programmer can ha...
by Silverlock
Thu Aug 20, 2020 2:34 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Old Meets New
Replies: 59
Views: 9059

Re: Old Meets New

It's alive! https://s3.amazonaws.com/gs-geo-images/f1981a28-0f55-4227-9f2e-41a77819748c.jpg Other than needing a manual reset to get started, up it came for the first time in I don't know how many years. At least a quarter century. I guess I get to sleep tonight. Now it's time to sit down with the m...
by Silverlock
Thu Aug 20, 2020 1:15 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Old Meets New
Replies: 59
Views: 9059

Re: Old Meets New

Interesting looking system - your original image was obviously really good but the forum engine has downsized it to what it considers to be an acceptable size resulting in loss of detail. What processor is it based on? I can see 'i' (For Intel) on a 40-pin IC but I can't read the number. Quite a we...
by Silverlock
Wed Aug 19, 2020 7:28 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Old Meets New
Replies: 59
Views: 9059

Re: Old Meets New

I made the mistake of reading this thread from the start. And I immediately remembered this wee beastie was sitting on a shelf in the basement.

Must. Resist. Temptation. I've already got enough projects on the go!

Image
by Silverlock
Thu Jul 11, 2019 4:49 pm
Forum: General programming discussion
Topic: regex question
Replies: 9
Views: 1296

Re: regex question

Try this: dynamic.6.name=wifi_linkqualup dynamic.6.source=iwconfig wlan0 | grep Link dynamic.6.regexp=Link Quality=(\d*)/?\d* dynamic.6.postprocess= dynamic.6.rrd=GAUGE dynamic.7.name=wifi_linkqualdw dynamic.7.source=iwconfig wlan0 | grep Link dynamic.7.regexp=Link Quality=\d*\/?(\d*) dynamic.7.post...
by Silverlock
Wed Jun 26, 2019 5:53 pm
Forum: Raspberry Pi OS
Topic: STICKY: Buster bug report thread
Replies: 392
Views: 99517

Re: Buster bug report thread

Short problem description: Audio truncation on playback Steps taken to produce: Downloaded the 2019-06-20 Raspbian Buster Lite zip file. Verified the sha256 sum. Unzipped the img file and dd'd it to a 16GB SanDisk Ultra uSD card. Inserted the card into a 3B with only the following plugged in: HDMI m...
by Silverlock
Mon Jun 24, 2019 6:17 am
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 945
Views: 178533

Re: Pi4 Thread - general discussion

Wow. Just wow.
by Silverlock
Thu Jun 20, 2019 10:18 pm
Forum: Beginners
Topic: How to turn on a LED
Replies: 8
Views: 1302

Re: How to turn on a LED

And the breadboard you're using has split ground and power buses. Your ground wire is on one side of the split ground bus, and your resistor to ground is on the other side. Add a jumper between the two ground lines shown inside the red circle and then see what happens.
Separate power buses.jpg
Separate power buses.jpg (186.35 KiB) Viewed 1277 times
by Silverlock
Sun Jun 09, 2019 11:38 pm
Forum: Troubleshooting
Topic: espeak and aplay broken
Replies: 9
Views: 5481

Re: espeak and aplay broken

Does this mean I should roll back the kernel then? I've done it once or twice on an x86 linux PC but how is that done on a pi? Thanks P.S. just checked and on the good Sd card I'm running "Linux raspberrypi 4.14.70-v7+ #1144 SMP Tue Sep 18 17:34:46 BST 2018 armv7l GNU/Linux" according to uname -a ....
by Silverlock
Sun Jun 09, 2019 11:33 pm
Forum: Troubleshooting
Topic: espeak and aplay broken
Replies: 9
Views: 5481

Re: espeak and aplay broken

Odd; for me it fails on both audio jack and HDMI, aplay cuts out on "Front cen" in both cases as described ... I forgot about HDMI audio; oops, mea culpa. Okay, it happens with HDMI and the audio jack, but there is at least one USB audio adapter that seems to work fine with the new kernel. It's not...
by Silverlock
Sun Jun 09, 2019 7:40 pm
Forum: Troubleshooting
Topic: espeak and aplay broken
Replies: 9
Views: 5481

Re: espeak and aplay broken

I reported a likely related problem with audio output from the 3.5mm jack in the thread Audio playback truncation with kernel packages 1.20190517-1 . I was able to reproduce the problem you're having with espeak and aplay with kernel 4.19.42-v7+ (package version 1.20190517-1). No audio from espeak, ...
by Silverlock
Sat Jun 08, 2019 5:05 pm
Forum: Python
Topic: [Solved] Extract table data from icon name with BeautifulSoup
Replies: 5
Views: 738

Re: [Solved] Extract table data from icon name with BeautifulSoup

I'm happy to hear that it worked out; you're welcome. Good luck with your project.
by Silverlock
Fri Jun 07, 2019 12:55 am
Forum: Python
Topic: [Solved] Extract table data from icon name with BeautifulSoup
Replies: 5
Views: 738

Re: Extract table data from icon name with BeautifulSoup

Quick & Dirty code fragment:

Code: Select all

for td in html.findAll('td'):
    img=td.find('img')
    if img:
        print img['src'],img['title']
If you've got more than one table on the page, you'd want to find the table first, then do the findAll() on the table rather than the whole file.
by Silverlock
Sun Jun 02, 2019 7:08 am
Forum: Troubleshooting
Topic: Recently upgrade my Raspberry Pi 3 with Raspian and now videos are broken.
Replies: 3
Views: 470

Re: Recently upgrade my Raspberry Pi 3 with Raspian and now videos are broken.

Is this happening in Chromium? If so, see here for the symptom and a solution.
by Silverlock
Fri May 31, 2019 10:50 pm
Forum: Beginners
Topic: crontab always empty, but jobs are running
Replies: 14
Views: 1489

Re: crontab always empty, but jobs are running

If there's nothing in the syslog file, I would have to wonder if perhaps cron isn't the culprit.
by Silverlock
Fri May 31, 2019 9:04 pm
Forum: Beginners
Topic: crontab always empty, but jobs are running
Replies: 14
Views: 1489

Re: crontab always empty, but jobs are running

Here's a potentially dumb question. Have you looked in /var/log/syslog to see if there's any logging info that might shed light on what's going on?

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