Search found 1189 matches

by czietz
Mon Aug 10, 2020 5:43 am
Forum: Hardware
Topic: Identify This Board?
Replies: 27
Views: 973

Re: Identify This Board?

Great work Christian. Would you mind providing the disassembler output. I think it is more useful than seudocode. See attachment. It's an export from my Ghidra project, i.e., it would need some post processing before you can assemble it again. disassembly.txt It is likely that READ is blocked and d...
by czietz
Sun Aug 09, 2020 4:38 pm
Forum: Hardware
Topic: Identify This Board?
Replies: 27
Views: 973

Re: Identify This Board?

Zippy wrote:
Sun Aug 09, 2020 4:12 pm
I can send you the PCB if you want to do further analysis on it?
Yes, thank you! Now that I've gotten so far, I'd really like to know if my assumptions about the flip-flip and NAND gate connections are right.

I'll send you my address via PM.
by czietz
Sun Aug 09, 2020 1:00 pm
Forum: Hardware
Topic: Identify This Board?
Replies: 27
Views: 973

Re: Identify This Board?

I can't be sure because I cannot see all the PCB traces. But P2.5 seems to gate the "read data" line, i.e., the line where data is being transmitted from the floppy to the computer/controller, by using the NAND gate. If I understand it correctly, the "step_one_track_higher" and "step_one_track_lower...
by czietz
Sun Aug 09, 2020 10:49 am
Forum: Hardware
Topic: Identify This Board?
Replies: 27
Views: 973

Re: Identify This Board?

As for the timing: Let's assume the crystal (or ceramic resonator) marked "6000" is a 6 MHz model, which is plausible, because this is the maximum clock frequency of a 8048. In that case, one instruction cycle takes 2.5 µs (=15 clock cycles). If I didn't miscount, the "delay" routine referenced abov...
by czietz
Sun Aug 09, 2020 9:41 am
Forum: Hardware
Topic: Identify This Board?
Replies: 27
Views: 973

Re: Identify This Board?

There are still too many traces obscured for a full reverse-engineering (without actually having the PCB to probe). Here's what I figured out, though: 8048 outputs: - P2.0 is presumably (not traced!) somehow controlling the drive select. - P2.4 is connected via two inverters to the step line of the ...
by czietz
Sat Aug 08, 2020 7:29 pm
Forum: Hardware
Topic: Identify This Board?
Replies: 27
Views: 973

Re: Identify This Board?

Couple of hi-res pics of the board here, might help: Thank you! Although, unfortunately, there are a lot of traces (actually, the most interesting ones) going under ICs; in particular under the 74LS04/05 inverters. So, it's next to impossible to reverse-engineer the schematics without actually havi...
by czietz
Sat Aug 08, 2020 4:15 pm
Forum: Hardware
Topic: Identify This Board?
Replies: 27
Views: 973

Re: Identify This Board?

The PCB might be doing something with step handling, i.e., seeking to a track. I can see that it counts events on the external interrupt pin. Depending on the state of a pin on port 1 (perhaps connected to the direction signal?) it increments or decrements a variable which it checks against the limi...
by czietz
Sat Aug 08, 2020 3:35 pm
Forum: Hardware
Topic: Identify This Board?
Replies: 27
Views: 973

Re: Identify This Board?

ROM loads fine in Ghidra and it looks like sensible 8048 code. It's a bit hard to tell what it is doing, though, without someone tracing the schematic of the thing. I.e. I can see that it's reading stuff from port 1, setting and clearing bits on port 2 and using the external interrupt. But what are ...
by czietz
Sat Aug 08, 2020 2:07 pm
Forum: C / PASCAL etc.
Topic: Compiling gcc 10.1.0 question
Replies: 13
Views: 338

Re: Compiling gcc 10.1.0 question

Thanks for the info, that is definitely worth a look. But i guess there must also something else going wrong, because a) the memset is not emitted when i remove the first loop in the example, only leaving the loop that initializes the array That's because in that case the loop is already unrolled b...
by czietz
Sat Aug 08, 2020 11:17 am
Forum: C / PASCAL etc.
Topic: Compiling gcc 10.1.0 question
Replies: 13
Views: 338

Re: Compiling gcc 10.1.0 question

FYI: In the case of your example code (posted with the GCC bug report), the memset function is added by the "ldist" optimization pass. "ldist" = loop distribution. Some archs have an optimization pass at RTL level which removes small size memsets again, which is why you don't get a call to memset() ...
by czietz
Tue Aug 04, 2020 7:58 pm
Forum: Hardware
Topic: Ultra Satan Driver
Replies: 4
Views: 185

Re: Ultra Satan Driver

You cannot simply put the driver in C:\AUTO. You have to use a special installer tool provided with the driver that will install (part of) the driver in the first sector of the disk (or SD card, in your case). TOS 1 has the capability of loading and executing the first sector from an ACSI drive - no...
by czietz
Sun Aug 02, 2020 2:04 pm
Forum: Coding
Topic: Atari SFP-004 FPU (Mega ST/STE) by example
Replies: 3
Views: 282

Atari SFP-004 FPU (Mega ST/STE) by example

There is very little documentation how to use the FPU in the Mega ST (SFP-004 addon card) and Mega STE (optional upgrade) from a programmer's perspective. For this reason, I wrote down my notes to give a small example. Please note that this is not meant as a reference or complete tutorial. It is mer...
by czietz
Sat Aug 01, 2020 1:21 pm
Forum: C / PASCAL etc.
Topic: pascal bug? integer word val shl ? loop
Replies: 8
Views: 250

Re: pascal bug? integer word val shl ? loop

Well, obviously you cannot shift q, being an Integer, by more than 16 bits to the left. Type-cast it to Longint before shifting, like so:
[...]
x:=(longint(q) shl(ln-i));
[...]
by czietz
Wed Jul 22, 2020 8:06 am
Forum: Hardware
Topic: Identify This Board?
Replies: 27
Views: 973

Re: Identify This Board?

I guess it's basically the same circuit that was built into some (but not all!) SF354:
https://www.nightfallcrew.com/wp-conten ... G_9773.jpg
Must do some kind of translation between computer and floppy drive, but I don't know its exact purpose.
by czietz
Tue Jul 21, 2020 6:25 am
Forum: Applications
Topic: Python
Replies: 5
Views: 324

Re: Python

There are ports of Python 2 and 3 by Thorsten Otto: https://tho-otto.de/crossmint.php. I expect these to run under MiNT only and not under plain TOS, but I haven't tested that.
by czietz
Sat Jul 18, 2020 12:01 pm
Forum: Hardware
Topic: Blitter for STfm worth it/needed?
Replies: 5
Views: 390

Re: Blitter for STfm worth it/needed?

Originally the Blitter was intended to speed up OS graphics calls, like window moving and scrolling or text drawing. Presumably, sequencer software makes use of these calls [1] and would therefore feel much "snappier" with a Blitter. That being said, there are also software solutions that offer a mu...
by czietz
Fri Jul 17, 2020 5:41 am
Forum: Hardware
Topic: Announcing the Lightning ST - USB & IDE for STs
Replies: 74
Views: 19066

Re: Announcing the Lightning ST - USB & IDE for STs

Still no shipping to the US though? That's what I'm waiting on before purchasing... :( German postal service has still suspended transport of small commercial parcels ("Warenpost International") and most other parcel post products to the US, I'm afraid. They state it's "until further notice", i.e.,...
by czietz
Wed Jul 15, 2020 2:23 pm
Forum: Hardware
Topic: NEW IDE Controller & TOS 2.06 board (with extras)
Replies: 743
Views: 192609

Re: NEW IDE Controller & TOS 2.06 board (with extras)

PlasticParty wrote:
Tue Jul 14, 2020 11:02 pm
Thank you for that. I tried sending an email to the guy but it didnt seem to send. I have posted a message on that topic.
Sorry about that. Please see my answer in the other thread.
by czietz
Wed Jul 15, 2020 2:22 pm
Forum: Hardware
Topic: Announcing the Lightning ST - USB & IDE for STs
Replies: 74
Views: 19066

Re: Announcing the Lightning ST - USB & IDE for STs

I am very interested in purchasing a Cloud and Lightning ST. Are they still available? I tried to send an email to the address in the first post but it said it was not recognised. Is anyone able to help advise? Yes, they are still available -- as is our 8 MB alternate RAM upgrade Storm ST. I hear t...
by czietz
Sun Jul 12, 2020 10:26 am
Forum: Hardware
Topic: Atari STe SD card reader on the Extended Joystick Port
Replies: 45
Views: 2762

Re: Atari STe SD card reader on the Extended Joystick Port

Great Idea,well done! I love the fact it's such a cheap solution and doesn't need the case to come off. I guess the downside is that you need to rely on the floppy to boot. EmuTOS has a SD card driver that can be easily adapted to new hardware. (In fact, it only took me a few hours to make it work ...
by czietz
Sun Jul 12, 2020 9:30 am
Forum: Hardware
Topic: NEW IDE Controller & TOS 2.06 board (with extras)
Replies: 743
Views: 192609

Re: NEW IDE Controller & TOS 2.06 board (with extras)

You can get TOS 2.06, IDE and USB(!) for the 520 STfm with the combination of Lightning ST and Cloudy: See the following links for more information: https://www.atari-forum.com/viewtopic.php?f=15&t=37225 https://www.atari-forum.com/viewtopic.php?f=15&t=37963&p=388528 http://wiki.newtosworld.de/index...
by czietz
Mon Jul 06, 2020 2:29 pm
Forum: Games - General
Topic: WIP: ScummVM-Lite Atari
Replies: 108
Views: 8384

Re: WIP: ScummVM-Lite Atari

I was shown this last weekend and I was really impressed how well it ran even on an ST. And of course it's a real joy on the TT accelerated to 48 MHz by means of our Speedy card. Well done!
by czietz
Mon Jul 06, 2020 1:33 pm
Forum: Hardware
Topic: USB drivers: CD/DVD-RW support
Replies: 23
Views: 1701

Re: USB drivers: CD/DVD-RW support

No answer from Lotharek so far regarding this. In any case I have added to the driver the option for the user to enable the overcurrent protection mode that for now is disabled by default. I had the opportunity to measure the available current myself on a NetUSBee (Lotharek version). OCP works -- o...
by czietz
Tue Jun 30, 2020 6:57 am
Forum: MiST
Topic: MiST in 2020
Replies: 33
Views: 1582

Re: MiST in 2020

I've found it to be noticeably faster. VDI / line-A text drawing is somewhat slower than with Atari TOS, Copying from a post on the EmuTOS Facebook page: "It's often repeated but nevertheless it's a misconception: EmuTOS's VDI (graphics routines) is *not* much slower than Atari TOS's VDI! There has...
by czietz
Sun Jun 28, 2020 7:11 am
Forum: Hardware
Topic: Atari STE: Drive A: diplays files with cryptic extensions
Replies: 29
Views: 882

Re: Atari STE: Drive A: diplays files with cryptic extensions

I realized that the characters of the extensions are replaced everytime with exact another symbol. Like missing a bit or taking it from another character set You're right about that. Assuming that the correct file name is e.g. "GEMDEMO2.BAS", you need to take away bit 6 to get to "GEMDEMO2.⇩⇧3" (wi...

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