Search found 44 matches

by ChrisTG
Sat Jan 02, 2016 4:31 pm
Forum: Hardware
Topic: Gotek help
Replies: 13
Views: 3012

Re: Gotek help

You're welcome! Nice to hear that it works for you, too. :cheers:
by ChrisTG
Fri Jan 01, 2016 10:11 pm
Forum: Hardware
Topic: Gotek help
Replies: 13
Views: 3012

Re: Gotek help

if you are running the Gotek with it's original Firmware, you need to modify the circuit so that the Atari machines can detect the media change.
Have a look here: http://www.tonmann.com/2014/08/gotek-fl ... -atari-st/ (The sorry subject detecting media(disk) change)
by ChrisTG
Sat Sep 26, 2015 12:33 pm
Forum: Hardware
Topic: BAD DMA - Myth or fact ?
Replies: 75
Views: 24249

Re: BAD DMA - Myth or fact ?

I think I will try my approach with 3x 74ACT14 and 8x 1k resistors. Using inverting schmitt-triggers and 1k resistors looks like a good plan to me.
Ordering parts now, we'll see how it comes out when it is built and running. ;-)
by ChrisTG
Sat Sep 26, 2015 11:43 am
Forum: Hardware
Topic: BAD DMA - Myth or fact ?
Replies: 75
Views: 24249

Re: BAD DMA - Myth or fact ?

Yep , I really wish the internals of the ST chips were published, it would make life so much easier. Yes indeed, it would a lot. :roll: I'm thinking about building a small pcb with a simple bus-holder circuit based of two inverters and a resistor per data-line, like described here: https://en.wikip...
by ChrisTG
Sat Sep 26, 2015 11:01 am
Forum: Hardware
Topic: BAD DMA - Myth or fact ?
Replies: 75
Views: 24249

Re: BAD DMA - Myth or fact ?

Btw, the "1v pulses" are crosstalk from a nearby line while the particular line is in "floating" state. So just another indication for a bad circuit design concerning the DMA stuff. Edit: The signals generated by the GLUE seem to have the same strange "floating" states,...
by ChrisTG
Sat Sep 26, 2015 9:47 am
Forum: Hardware
Topic: BAD DMA - Myth or fact ?
Replies: 75
Views: 24249

Re: BAD DMA - Myth or fact ?

Hm, I still believe that some circuit that keeps the signals on the last valid state would make sense as it would also eleminate all that inexplicable timing issues that we had to fight against in the past when building new hardware for the ACSI bus. IIRC Jookie had a lot of trouble with the timing ...
by ChrisTG
Sat Sep 26, 2015 9:06 am
Forum: Hardware
Topic: BAD DMA - Myth or fact ?
Replies: 75
Views: 24249

Re: BAD DMA - Myth or fact ?

I did some measuring myself using a cheap USB-based logic analyzer yesterday. I can confirm the observations of exxos: The DMA-chips seem to have some fault in their design resulting in intermediate undefined (or tristate) signals on the data bus. If you study the rest of the schematic, you will see...
by ChrisTG
Thu Sep 24, 2015 9:47 pm
Forum: Hardware
Topic: DMA & Floppy issues on STFM modification
Replies: 29
Views: 7946

Re: DMA & Floppy issues on STFM modification

Chris, did you already try some schmitt-trigger ic instead of a buffer? Maybe this could cure the "floating" signals better. However, you'll need some bidirectional trigger ic which I'm not sure if it actually exists.
by ChrisTG
Wed Sep 16, 2015 7:01 pm
Forum: Hardware
Topic: Gotek Floppy Emulator
Replies: 122
Views: 50608

Re: Gotek Floppy Emulator

but that thread deals with a standard floppy, not a gotek. If I put the old floppy back in I get perfect read/write to and from both drives. Only the gotek has problems. No, not quite correct. It deals with the general DMA-issues your ST may or may not have. And these problems most likely arise whe...
by ChrisTG
Sun Sep 13, 2015 5:28 pm
Forum: Hardware
Topic: Gotek Floppy Emulator
Replies: 122
Views: 50608

Re: Gotek Floppy Emulator

I just got a gotek preflashed with the latest HxC. It works nicely as A: alongside the physical B: but writing to .hfe images produces garbled data. If I copy a floppy with fcopyIII to the gotek with formatting and verifying on, I get 50-100 "bad checksum when verifying" errors. If I pres...
by ChrisTG
Sun Sep 13, 2015 1:22 pm
Forum: Hardware
Topic: DMA & Floppy issues on STFM modification
Replies: 29
Views: 7946

Re: DMA & Floppy issues on STFM modification

More testing with the 001 DMA. After removing the pull downs on the data bus, I again get floppy problems. So neither -38 DMA, or 001 DMA is working correctly in the STFM. As posted above, the -38 DMA needs pull ups, the 001 needs pull downs. I am still trying to figure out why. Hm, the scope lines...
by ChrisTG
Fri Aug 21, 2015 4:54 pm
Forum: Hardware
Topic: Gotek Floppy Emulator
Replies: 122
Views: 50608

Re: Gotek Floppy Emulator

So did you add a HD mod to the floppy controller yet? The floppy-controller already needs to be fitted for HD-operation (e.a. run at 16MHz instead of 8MHz).
by ChrisTG
Thu Jul 30, 2015 5:59 pm
Forum: Applications
Topic: Looking for "WebLight" Webserver Software
Replies: 1
Views: 1881

Re: Looking for "WebLight" Webserver Software

Yet tried Google? :coffe:
by ChrisTG
Sun Jul 26, 2015 1:31 pm
Forum: Hardware
Topic: 1040 STF repair help
Replies: 18
Views: 5525

Re: 1040 STF repair help

The are one or two big electrolytic caps near the power connector on the MB, these may have dryed out. Then there's an important cap in the reset circuit that may be faulty so that the reset is too short when the machine is "cold". Also the reason for a machine running after a "warm u...
by ChrisTG
Sat Jul 25, 2015 11:45 am
Forum: Hardware
Topic: 1040 STF repair help
Replies: 18
Views: 5525

Re: 1040 STF repair help

Before you start changing each and every cap, I'd suggest to check wether there is actually the need to do so. I'd measure the ac-ripple on the dc voltages. To do so, first check if the dc voltages supplied by the psu are all in range and stable : 5V : ~4.90 to ~5.25 volts 12V : ~11.8 to ~12.8 volts...
by ChrisTG
Sat Jul 25, 2015 9:57 am
Forum: Hardware
Topic: New board: MonSTer
Replies: 553
Views: 110330

Re: New board: MonSTer

Does it work with a 16mhz-speeder like the ones build by exxos? Currently I have a DIY-solution here installed and it would be great if I could use it together with a neat alt-RAM upgrade.
by ChrisTG
Wed Jul 08, 2015 12:47 pm
Forum: Demos - General
Topic: Atari Links
Replies: 47
Views: 128750

Re: Atari Links

All shortlinks seem to be broken here ATM - can someone confirm this? 8O
by ChrisTG
Tue Jul 07, 2015 4:54 pm
Forum: Hardware
Topic: The LaST Upgrade - Part 18 - V1.5 16MHz CPU & ROM Booster
Replies: 26
Views: 8461

Re: The LaST Upgrade - Part 18 - V1.5 16MHz CPU & ROM Booster

Btw: How do I get TOS2.06 on the PLCC-ROM then?! :shrug: You can't run anything higher than TOS104 on a STFM by default. To use TOS206 you need a couple of extra GAL's & logic to do it. The V2 booster has this, but that is a long way off production. Damned, then it seems I got you wrong. I thou...
by ChrisTG
Tue Jul 07, 2015 1:33 pm
Forum: Hardware
Topic: The LaST Upgrade - Part 18 - V1.5 16MHz CPU & ROM Booster
Replies: 26
Views: 8461

Re: The LaST Upgrade - Part 18 - V1.5 16MHz CPU & ROM Booster

Btw: How do I get TOS2.06 on the PLCC-ROM then?! :shrug:
by ChrisTG
Tue Jul 07, 2015 1:21 pm
Forum: Hardware
Topic: The LaST Upgrade - Part 18 - V1.5 16MHz CPU & ROM Booster
Replies: 26
Views: 8461

Re: The LaST Upgrade - Part 18 - V1.5 16MHz CPU & ROM Booster

Cool, I just ordered the v1.5 + Rom kit :P
by ChrisTG
Sun Jun 28, 2015 10:56 am
Forum: Hardware
Topic: Anything like Overscan for STE - is it possible?
Replies: 5
Views: 1901

Re: Anything like Overscan for STE - is it possible?

Hi, thanks for your replies. @troed: I know about the DE-problem but I thought someone may have build a solution to bypass this limitation of the STE. IIRC the DE is something like the CE on ROMs, so it should be possible to manually extend the signal duration for the shifter if one puts a dedicated...
by ChrisTG
Sat Jun 27, 2015 3:47 pm
Forum: Hardware
Topic: Anything like Overscan for STE - is it possible?
Replies: 5
Views: 1901

Anything like Overscan for STE - is it possible?

Hi,

I wonder if something like Overscan or Lacescan could be done with the STE, too?
Has anyone yet tried to build a (simple) hardware-mod that extends the screen resolution?

cheers
Chris
by ChrisTG
Thu Jun 25, 2015 11:48 am
Forum: Hardware
Topic: The LaST Upgrade - Part 18 - V1.5 16MHz CPU & ROM Booster
Replies: 26
Views: 8461

Re: The LaST Upgrade - Part 18 - V1.5 16MHz CPU & ROM Booster

Ah, okay. Then I think I'll give it a try. :cheers:
When will it be buyable in your shop?
by ChrisTG
Thu Jun 18, 2015 6:35 pm
Forum: Hardware
Topic: The LaST Upgrade - Part 18 - V1.5 16MHz CPU & ROM Booster
Replies: 26
Views: 8461

Re: The LaST Upgrade - Part 18 - V1.5 16MHz CPU & ROM Booster

So normal 27Cxxx eproms on a TOS expansion card are too slow?
Is there any chance that it will work with TOS 2.06, too?

regards,
Chris

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