Breadbin Repair - Black Screen

[carlsson]

So is the SDrive-MAX a 100% solution for the Atari 8-bits? In the lower price range for the Commodore you have the SD2IEC and uIEC/SD type devices but as you know those have certain limitations if you have come across a library of original floppy disk images or scene demos. I suppose the UK1541 might be an middle of the road solution but I don't know if it still is in production.

 

But yes, the Pi1541 is intended for people who already have a suitable spare RPi to connect it to. I agree that if you factor in all costs, it isn't quite as cheap as it first may look.

[+DrVenkman]

1 hour ago, carlsson said:

So is the SDrive-MAX a 100% solution for the Atari 8-bits?

It can be for most folks. As far as I know, it has two limitations (potentially 3 but that’s a pretty easy fix, as I will try to explain.

 

It does not yet support creating double-density disk images, only single density (90K) and the Atari 1050 “Enhanced” density (130K). That’s fine for most people who are using stock, unmodified vintage machines. It does not yet support creating larger ATR images on the device itself, though you can create empty ones of any size you like up to 16MB on any other device and load them onto the card. It’s a known limitation and I believe it’s on the list for the dev team to add.

 

It does not do 100% 6502 emulation as does the Pi1541. Therefore you can’t use it to replace the various Atari drive enhancements like Happy drives, Archiver, The Chip, Lazer, Speedy, etc. While it does handle ATX files very well (copy-protected disk images created from clean Kryoflux or SCP magnetic flux images), it does so by emulating response timings based on a clever scheme that encodes that stuff into the ATX file format). However, the lack of Happy/etc. emulation is not really a limit for most people. Those who do have physical drives with enhancements (like me), often have more than one drive and like to play around with real disks for fun only - we’re not using them “seriously” every day; we nearly always have a CF card or SD card device to use a primary storage. The physical drives are just an additional bit of fun.

 

Finally, the way the Arduino I/O pins are wired internally, the device “steals” the SIO bus and there are usually problems using the basic SDrive-MAX with other SIO devices. For instance, you probably won’t be able to use a physical floppy drive at the same time as the SDrive-MAX. However the workaround for this is pretty straightforward: AA user BigBen figured out how to create a little data buffer circuit to isolate the Arduino I/O pins from direct connection to the SIO bus and thus prevent the “stealing” that goes on. AA user MrRobot then created a series of little boards implementing this circuit - the latest one costs only a couple bucks to build and can be pretty easily installed into the device and allows complete interaction between all your various devices without a problem. If you don’t use physical drives, this is all a side issue and not a problem at all and the buffer circuit is unnecessary. 

 

But having said all that, a single devices that gives emulation of four floppy drives at once using either ATR or ATX files, a tape drive, and XEX (executable) files is pretty great. Many hobbyists don’t need anything else. 

[motrucker]

1 hour ago, carlsson said:

So is the SDrive-MAX a 100% solution for the Atari 8-bits? In the lower price range for the Commodore you have the SD2IEC and uIEC/SD type devices but as you know those have certain limitations if you have come across a library of original floppy disk images or scene demos. I suppose the UK1541 might be an middle of the road solution but I don't know if it still is in production.

 

But yes, the Pi1541 is intended for people who already have a suitable spare RPi to connect it to. I agree that if you factor in all costs, it isn't quite as cheap as it first may look.

The Pi1541 is definitely aimed more towards tinkerers with a drawer full of Pi, Tinker Boards, etc. . A very nice 1541 alternative though.

 

[carlsson]

Btw, I've been happily using uIEC/SD for about 10 years now. Rarely or never I got into trouble with programs implementing their own fastloaders but then again I am aware about its limitations and choose my usage based on what it can do, instead of nagging online about what it can't do. Not until recently I was aware there are large online libraries of original D64/G64 dumps, besides the cracked, often single filed versions.

[+DrVenkman]

Just now, carlsson said:

Btw, I've been happily using uIEC/SD for about 10 years now. Rarely or never I got into trouble with programs implementing their own fastloaders but then again I am aware about its limitations and choose my usage based on what it can do, instead of nagging online about what it can't do. Not until recently I was aware there are large online libraries of original D64/G64 dumps, besides the cracked, often single filed versions.

I’ve been playing with some of those G64 files on the Pi1541. There’s a great archive of stuff up on Archive dot Org that I loaded up onto my microSD card.  So far I’ve only found a couple titles that don’t seem to load properly (Rastan, for instance). Every time I try to load that game the activity light on the Pi1541 just begins blinking rapidly and the Pi locks up. I presume that either these files are corrupted somehow or it’s a bug in drive emulation (I’m using the .20 version of the kernel image downloaded from the project home page). 

 

Anyway, it’s been a lot of fun playing around and fixing up this system. But boy howdy, if I keep messing with it, I will *have* to put JiffyDOS into it. Jeez is serial I/O slow on these boxes. I know the back story of how and why it is the way it is, but still ... ugh. That’s a painful bug in the stock design.

[carlsson]

You can plug in a cartridge to get some more speed out of it. Not sure how much cheaper it would be than installing JiffyDOS but far easier. TFC3 or any of the Action/Retro Replay cartridges tend to give you a decent bump up.

[+DrVenkman]

The saga of my C64 "Deadbin" has reached a happy plateau. The Nano SwinSID I ordered on Friday arrived today and is living happily inside the board and seems to work pretty well. Bottom line: most sound effects and music sounds very good. The more heavily filtered and processed the sound, however, the more defects become apparent. I've uploaded three samples to YouTube. Pardon the crappy video quality but I just made fast handheld captures with my phone to demonstrate.

 

First up, Bubble Bobble:

 

 

Next up, Rastan:

 

 

Both of sound good-to-excellent. But listen to the opening bits of Alien:

 

 

The video is a bit long but that's on purpose: you can hear the emulation accuracy actually changing throughout as the microcontroller core tries to handle the very heavily processed sound normally produced by the SID's oscillators and filters. 

 

Now by contrast, this track (Batman The Movie) sounds really great.
 

 

Anyway, my friend has offered to sell me a genuine 6581 from one of his parts boards, and just for grins I might also see about buying an Ultimate SwinSID if/when they become available, just for comparison (yes, I know I've already spent more than enough money on this silly Deadbin, but it's been a fun learning project!).

 

*****

So to sum it all up, to get this machine usable again, I've had to replace the PSU, the PLA, the SID and two 4164 DRAMs. Along the way as part of testing I've also replaced the two MOS 7708's with new 74LS257's but ironically that wasn't necessary as both the originals still work once the new PLA and second dead DRAM were replaced).

 

Eventually I will likely install JiffyDOS or at least get some kind of fast-load cart, plus a genuine replacement SID from my pal, but for tonight, I'm "done." Ish.  

Edited July 24, 2019 by DrVenkman
Fixed link

[shoestring]

Still sounds great and better than no sound at all.

 

I hear that fpgasid is pretty accurate but not exactly cheap!!

 

Enjoy!