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Hi, I´m very sorry - I forget to mention this fact in the installation manual and my hardware "catalogue" as well Of course I will offer a full refund, if you want. Just PM me. There´s no really good way to install it except direct soldering without the use of sockets. I don´t recommend that. Although I test every unit before shipping, and you also have test your computer, something may went wrong. And with a fixed, not replaceable PCB like this any kind of service is hard - maybe impossible. Desoldering a machine-head contact strip is pain in the *** - the chance of destroying any trace is much higher. I updated the manual and catalogue files parallel with this post. If anybody has bought this PCB for usage in a 600XL, please contact me. Jurgen

Hmmm.... this would be TOO easy

You should exchange the PIA for test before you change all these small 74s logic chips. The possibility of a defect PIA is much higher. For example, when PB7 (portbit 7) is defect, the whole OS won´t start with a XL/XE operating system. During coldstart they set PB7 to low (mirror selftest in the memory area $5000-$57FF) and then the OS jumps into the memory detection and zeropage/stack-page test routine. If PB7 can´t set to low by a write access to $D301 in case of a defect, then the CPU jumps to elsewhere and hung up - black screen at all. So go ahead with PIA. Or, if you can, burn a EPROM with a OLD-OS from 400/800 series and plug it in. These OS versions doesn´t toggle PB7 and run also with a defect PIA.

Such a thing the best professional will happen, never mind. But you can breathe - this side of the 74LS375 is unused at the standard 800XL mainboards. Only on the 600XL mainboard both FlipFlops are used, and at the 1200XL, too. But the 800XL without freddie has the pins 1...7 simple NC - not connected.

When no offers from the U.S. comes in, sent me a PN and I will make such a cable. Jurgen

The color crystal (4.336 MHz) is only needed for PAL color carrier frequency. The chance that a standard crystal went bad is extremly low. I´ve had a few times a defect 74LS74 when the display hasn´t had colour, just b/w. But in your case there´s nothing on the screen, so mising colour may be the 2nd order issue IMHO. As wrote in other posts, I don´t see the capacitors in scope. Only the 470 uF behind the power connector at XE mainboards or the both 470 uF capacitors behind power connector and OS-ROM at the "Rose" 800XL mainboards (with freddie) should be replaced by default. Never have had the need for others, IMHO in the 80s were better quality used until Tramiel & co. "optimizes" the business.

First: Sent back this converter box. I NEVER have seen (or purchased) one of them really useful or with good quality. IMHO you look for other solutions (more than one monitor etc.) or buy a "Framemeister" for a lot of money. But´s nothing compares to the Framemeister Maybe you look for another TV - and I mean "TV", not computer monitor. Personally I didn´t know any CRT monitor which can display NTSC and PAL. Here in PAL-land all classical monitors like Philips CM833 and it´s similar brands are PAL-only. For NTSC gaming I have bought an old Goldstar television some years ago. It was made for PAL, has a typical SCART connector (normally not found @ NTSC TV). but can display NTSC, PAL and SECAM w/o problems. IMHO the last CRT TV´s made in the 90s have multi-norm circuits. It´s cheaper to take the ready-to-use designs supporting all TV norms. Such a TV should be also availible in the US...

Thanks for interest. Yes, I do. sent you a PN with details. Jurgen

Here it is. It´s a executable binary (.COM or .XEX). It just programs drive #1. UNHAPPY.XEX

Hmm - when you remove the OS-ROM, the background should turn red/brown. If not, anything is wrong. I think, before spending more and more money to buy replacement parts, it´s better to get help by an UK hardware professional like FJC. Without scope and the needed skills we could exchange 50 posts and more

Speedy supports the same features like the Happy 1050: - Disable the trackbuffer (as you mentioned) - Loading the genuine 1050 firmware into Speedy RAM Disabling the track buffer is only enough for very old protected disks. The newer (meaning from sight of the 80s) copy protection schemes based on FDC errors, 1050 firmware flaws and some things more, so just a disabled track buffer won´t help Using the Speedy Ulitity disk you can load the genuine 1050 firmware into the Speedy´s RAM and it will be executed - no difference to a stock 1050 anymore until next power-cycle. The same thing can be done with a Happy 1050 (or clone) using the "CSS Unhappy Maker 1050". Jurgen

Hi, let´s start from scratch. Remove OS-ROM, start computer. You monitor or TV should show a red/brown background. At this state we know: ANTIC/GTIA mostly working fine. System-clock is there. Color output is okay - you should run this test using a CVBS connection (standard DIN 5 pin to SCART etc. cable). Re-insert the OS-ROM, switch on again. When screen turns black, then CPU is working (maybe a little bit, but not totally damaged). Because you change already the CPU and CPU & RAM are the most significant defects I would focus on RAM circuit now. I assume you haven´t an oscilloscope (otherwise you would mention it already), so first idea is to change the following ICs - in exact these order: Both 74LS158, 74LS375, 74LS51. Also the MMU (the only one with 20 pins) could be worth a try. All these parts you have in your working 600XL Good luck!

The resistor is in the path of OPTION key to GTIA - so if it´s bad, always no connection would make, i.e. OPTION never could pressed - the S0...S3 inputs @ GTIA are low-active and have internal pull-up resistors. So without keyboard it would have no impact, as long the GTIA internal works fine. But, when the RAM test immediately starts, then - when - START would be the problem, not OPTION. I´ve seen this some times. In all cases the RAM has a defect. When computer starts, the coldstart subroutine will test the first 1024 bytes of memory. if any error, the self test is started. But, the selftest has some "dummy" tests. Not every byte & range is really tested. You find a delay loop in the code, which fakes the real time needed for the test-time of one square. Also the RAM test didn´t detect RAM errors below $0400 and in the range the self-test was mirrored in ($5000-$57FF). So changing RAM is the way forward IMHO.

Thank you very much for these infos. I´m astonished about the gap you mention. When I create the first Sys-Check boards and the prototype comes in, I try it in over 10 different XE mainboards, there wasn´t a gap of 1 mm possible when I´m remember right. Maybe I´m wrong, but 1 mm is too much to accept and can cause contact issues, of course. Wil check this again with my stock of XE boards and some Sys-Check PCBs. I change the PCB maker from Iteadstudio to AllPCB last year, maybe here´s a difference. All PCB orders based on the same gerber data files, never changed that since V2.2 is born. Strange...

I would check if all addresslines are proper connected to Freddie. Check A0...A15 from CPU´s pins to Freddie´s pin with your DMM. Start with A15 and count down, because I would suggest A13 is not connected through.

This was also my first thought. Have had this issue at some XE (and XL, too), that´s the reason why I have a "cleaning tipps" chapter in the Sys-Check manual. Did you also test Sys-Check with an arabic XE successfully like Jon? If so, I think there are more "positives" then the need to examine it by myself. And, I never heard of a different hardware setup, just an alternative operating system.

Hi Fred, thanks very much - But before we ship the computer, I will wait for more responses. BR Jurgen

Hi all, I know it´s not the right thread, but I´m sure, some owner of an arabic XE watch this I got two mails in the last 12 months from different user (one in USA, one in UK) that their arabic 65XE won´t work with my Sys-Check V2.2. Both computers have an ECI, of course. Reported issue is the same: Just a red/brown screen after Sys-Check is plugged in. Contacts were okay, one of them test the XE successfully with a KMK-IDE V2.0 IDE interface. Of course I´m interested what´s going in there, but I haven´t any arabic 65 XE in my collection. So I ask the community... does anybody own such a model, has also Sys-Check and test it? And, is there anybody who is willing to borrow me the mainboard (less shipping costs and risk of damages) for testing with Sys-Check? Thanks, Jurgen

I´m wondering that you didn´t have problems in the XE generally. I´m curious, how many systems you test? What is the Freddie´s marking in the XE computer where you have no issues? I´ve made the same thing >5 years ago, but this one works only fine in all XL except the "Rose" mainboard (with Freddie) - and also not in all XE / XEGS computers. When analyzing the issues I found out, that Freddie causes the problem. Using the 400/800 way to halt the CPU when ANTIC claims the bus causes PHI2 remaining high during a very long time sometimes (in relation to the standard PHI2 phase). Freddie itself uses PHI2 to synchronize DRAM access. When you connect a logic analyzer, you will see, that CAS sometimes remains high, even when the ANTIC/GTIA want to fetch data from RAM. In my version also PMG failures occur, also disturbation in high-res (Graphics 8 mode). So I dropped the whole thing, it was only a proof of concept.

Yes - but a seperated Covox board needs a lot of additional wiring. You´ve to connect 8 datalines, PHI2, RW, some address lines and more. This results in a messy mainboard with a lot of wires crisscross - I didn´t like that. And, it causes more problems than needed with a lot of support. I´m pretty sure that´s one of the reasons, why Lotharek never offers a new version of his old Covox solution. Second: If you have seperate stereo boards and Covox - how to mix the audio signals? You´ve to know the exactly used parts of the stereo board to gain best sound quality and mostly same volume level. And again, more wires needed. IMHO this was the way in the 80s, when some computers look like spaghetti monsters

You can replace the 4164 DRAMs on a 800XL mainboard with the 41256 without problems - at all 800XL mainboards pin 1 is connected via pull-up resistor to VCC. Of course only 800XL, when talking about a 800XE, just must connect all pin 1 to ground or +5 volts.

Hi, just a little note, I´ve updated the manual (no new firmware at this day - sorry). I correct some very little mistakes in the manual and remove the warning about usage Sys-Check with internal memory expansions. Thanks to the people who remind me Jurgen Sys-Check Files V2_2 Release 20180408.zip

CharlieChaplin also waits for Covox I planned to remove the problematic (and not populated) FTDI part on my Stereo Enhancement and add a Covox circuit. It´s the best place where such an add-on circuit should be. Will be ready this year... but I can´t say exactly when. Jurgen

I´m pretty sure that the keyboard itself is the problem. If POKEY or the 4051 mux chips would be the source of trouble, then at last one row of keys won´t work - but you told, in the "good phase" all keys are working fine. The 400 keyboard is extremly simple and cheap made of glued mylars. I don´t know any way to fix it, only a replacement keyboard (BEST Electronics oder MyAtari) will help.

Have finished today new Stereo Boards. Jurgen