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Joey Z

Member Since 14 Sep 2010
OFFLINE Last Active Nov 9 2018 8:13 AM

#3811358 SIO2PC USB daisy chained to 1050 - ISSUES

Posted by Joey Z on Fri Jul 21, 2017 9:28 PM

The Atari SIO bus is what's known as 'open collector' on the RX line (device --> Atari computer). This allows multiple devices to use the line without interfering with each other. The diode is a kludge that converts a normal push-pull signal into an open collector signal, and is generally good enough in this case. Without the diode, the FTDI can drive the line high and, if it drives hard enough, prevent the real disk drive from communicating.

#3804515 Apps & Utils You'd Like To See For: Atari GUI

Posted by Joey Z on Wed Jul 12, 2017 8:23 PM

Ah - good. So I don't have another drive to write. :)

What, you mean you don't like writing drivers?


I figured they were your favorite thing in the whole world, based on how much time and effort you put into APT drivers, for example. :-D

#3803163 Apps & Utils You'd Like To See For: Atari GUI

Posted by Joey Z on Mon Jul 10, 2017 8:53 PM

I said it in the other thread, I'll repeat it here: RPN desk calculator, this time see grpn for inspiration.

Bonus points if it could be based on the HP15C, or the 16C if not the 15. 15C has some more advanced operations as it's a scientific, 16C is the programmer's variant.

#3802000 Apps & Utils You'd Like To See For: Atari GUI

Posted by Joey Z on Sun Jul 9, 2017 8:40 AM

I said it in the other thread, I'll repeat it here: RPN desk calculator, this time see grpn for inspiration.

#3801999 Apps & Utils You'd Like To See For: Atari DOS

Posted by Joey Z on Sun Jul 9, 2017 8:39 AM

I know there are people who like to do things with their Ataris besides play games.


What apps & utils would you like to see for Atari DOS?

Also, what features would you like to see, or what apps & utils already exist that you would like to see upgraded with particular features?

[Note: There are separate threads for Atari GUI & Cross-Platform apps & utils.]


I'd Like To Create:

- ToDo / Calendar
There are features I've had in mind for many years, which I haven't found in any PC app (maybe I haven't searched hard enough). I think it'd be great to have on my Atari.

how about a nice RPN desk calculator? see unix dc for inspiration :)

#3801404 Atari 800 Help

Posted by Joey Z on Sat Jul 8, 2017 12:03 PM

does it pause as if it had beeped when you hold down start? The 800 has that internal speaker which could be broken, or disconnected.

#3784481 Not sure where to drop this / ataribox

Posted by Joey Z on Wed Jun 14, 2017 7:33 PM

It's not just you.  It's also about a zillion potential Atari customers (like my kids) who are too young to be into the retro-gaming scene, but nevertheless recognize and even revere the Atari name and legend because they've heard their dads talk about it so much.  In my opinion, that's the stuff Atari needs to tap into.

I think you overestimate the level of brand recognition that the Atari name has. Being rather young for this hobby myself (I'm 20) I can tell you most people my age have no clue what I'm talking about when I mention Atari. It's not going to get any better as the world grows up.

#3782798 600XL RAM upgrade fail :(

Posted by Joey Z on Mon Jun 12, 2017 8:06 PM

the last 4 numbers are just a date code, but also that chip is very expensive. These chips can be had for < $1 if you look in the right place. Try searching some other numbers:
First, leave off the N: 74LS158 (of any DIP package) will do
Also, there are several other variants which should work fine, 74ALS158, 74F158, 74HCT158, 74ACT158 will all work.

#3779465 NTSC core for VBXE?

Posted by Joey Z on Thu Jun 8, 2017 9:29 PM

Lotharek makes and sells the VBXE now but I believe candle is probably more involved in development since it went to V2 back around 2009.

And candle is pretty busy these days it seems, between children and work. The main issue being that it's going to be hard to get in contact and hold his attention, I think. Once he gets the chance to do it, I imagine it's not difficult to compile the HDL with a new palette.

VBXE uses a modified LAOO.ACT palette which is biased more towards PAL than NTSC.
I've looked at the flashable core file and can't see any embedded data which looks like a palette.  It's a fairly easy scan since the core files seem to have lots of grouped zeros and palette files don't.
My guess would be one of these:
- palette not contained within normally flashed core area?
- the palette is compressed or stored out of normal RGBRGB sequence?
- the palette is derived procedurally?

Most likely option C, the palette is stored in memory within the FPGA, and the memory initialization section of the FPGA core is compressed. Also, since VBXE only has 21 bit color IIRC, the bits may be packed weirdly. Not to mention the synthesis tool can really reorder the bits any way it wants in order to simplify routing within the FPGA. On top of that, modifying in place would be problematic as the Altera bitstream format apparently includes checksums. I actually did look into this, but it seems like an unreasonable amount of work to do.

The palette is 768 bytes so you may as well assume a 7-8 sector boot program to do your own every time if you go that route.
An alternative if you have a flashable multi-OS upgrade could be to do a modified OS.  Would probably be easiest to use the second character set to store the palette and initilization code which would only need to run on coldstart.

I had thought of disk boot for the fix, but this doesn't work so well with my cartridges (which probably mostly have DOS boot disabled I imagine). I had thought of using a modified OS already, I suppose that is possible. My other thought (more involved) was to make a dummy PBI device that performed this function (but that's way more involved, as I said).

It just seems to me the cleanest solution (the right way, if I may call it that) is to just make a different core with a proper NTSC palette, especially considering VBXE allows easy flashing of cores (via FC.COM).

#3779305 NTSC core for VBXE?

Posted by Joey Z on Thu Jun 8, 2017 5:16 PM

Well, I finally got around to installing my VBXE. As far as I know, there is no VBXE core that has NTSC colors for the palette by default. I imagine it's not too hard to update the core to contain a different palette, if one had the source.


Anyway, I believe Electron was the designer for the VBXE, and still retains rights to the core. Anybody know if he can be contacted to ask for an NTSC core? I don't even know if he speaks English....


I suppose you can load a new palette with software, but that won't be persistent between boots of course. I know we just went through this with the Sophia, does anyone remember what palette ended up being used there? Otherwise I have to look through the whole thread again....

#3776085 130XE project system, some revision questions.

Posted by Joey Z on Sun Jun 4, 2017 9:29 AM

I have removed 2 and 3 caps on the sio ports since I first started using high speed devices all those years ago... NEVER had a dead pokey on any machine... and it is the recommended action for most high speed drives... ICD US doubler, XF551,and the like.... notes from ICD as well as Atari told the caps to remove... so what are you talking about?

Capacitors on an externally exposed line are a very common form of ESD protection. That's possibly why they're there. You'll notice they have caps on just about any connector on the Atari that has male pins, and they can get away with the speed degradation. Ideally, you would use TVS diodes instead, along with a smaller cap in a situation like this (where the cap produces too much loading on the high-ish speed signal, not to mention it's an open collector line).

#3775398 Running Hias' High Speed SIO Patch within RespeQt

Posted by Joey Z on Sat Jun 3, 2017 9:03 AM

Also, I could send you an EPROM, except that all my EPROMs are at school.

#3775192 Running Hias' High Speed SIO Patch within RespeQt

Posted by Joey Z on Fri Jun 2, 2017 10:58 PM

I did do this with a 600XL.  No change at all.  Did you do this with a stock OS or a patched OS?
With my stock OS machines, I set RespeQt to 57600 but it transfers are all locked at 19200.  Not starting at 57600 and falling back - never anything but 19200.  It sure seems like RespeQt is sensing the lack of patched OS and over-riding the settings down to 19200.  This applies to two 600XLs, an 800XL and a 65XE.  The only exception is my 1200XL with the Warp+ 32 in 1.  It acts the same way with any of the base OSs such as XL, XE, etc... but will run steady at 57600 with the Warp+ OS loaded.

I've tried with Sloopy's SIO2PC-USB, a SIO2v23 and an old school SIO2PC with DE9 serial port.  All seem to work the same.  

I also have an SDrive NUXX.  I've mostly used it with the 1200XL and gotten very good speeds.  I'll try it with a couple of the others when I get a chance to see if they run any faster than they do with RespeQt.

No, RespeQt doesn't select high speed mode, the Atari has to negotiate it. If you're not running software that enables the high speed mode, it stays in 19200 at 1X speed. You need some kind of 'SIO patch.'

#3775188 130XE project system, some revision questions.

Posted by Joey Z on Fri Jun 2, 2017 10:49 PM

I used to get the same question from my wife at first when I started watching Louis Rossmann. Now it's "I'm off out. Are you going to watch your Louis?". :)

Never witnessed that yet, although I can't imagine it working well. I tried total voice control of my Android phone once and it was totally unreliable until I adopted an American accent, at which point voice recognition magically became completely accurate. But I can't realistically talk like that the whole time. :)

Yep: 600XL and 800XL only, and even then, the adventurous might be able to wedge Rapidus directly under the keyboard somehow (see Sloopy's Rapidus 600XL on Facebook). Adaptus isn't required for the 1200XL (indeed, it would not fit): instead, you must make your own adapter to offset the CPU socket by half an inch or so to prevent the CPU blocking the keyboard. Not sure about the XEGS, but I guess it would plug right in there.

PS: Top tip is to leave the bottom RF shield on the machine. Put it back on the 800XL featured in the video half an hour or so ago, and it hasn't rebooted yet. Will feature this in a video assuming it isn't a total fluke.

Sounds like it's coming down to RFI again. Who knew putting 160MHz clocks in a system from the 1980's was a bad idea....

#3773656 New development: GTIA in CPLD

Posted by Joey Z on Wed May 31, 2017 7:25 PM

OK, give this a try.


Changes:  The PM0 is now at the edge of the screen, the program now puts up color pattern #1010 (PF1 - Green) on screen.  This detection relies on the Graphics 10 shift.  Stock Atari shifts it one color clock right, but Sophia leaves it unshifted.  So in theory, the collision register will not be tripped on a stock Atari, but should be tripped on a Sophia-equipped Atari.  Someone try this out please?



I think you're misunderstanding the issue. Sophia cannot be read, only the original GTIA can be read. Sophia only 'snoops' for GTIA writes and uses them to reproduce only the video output picture. The original GTIA is what performs the collision detection still, and responds to all other register reads, as I understand it. You can't possibly detect Sophia if you can't read anything from it.