mk79 wrote:Do you by any chance know if this PCB is pre-Samsung?
To distinguish between THORN (EMI) DATATECH UK made QLs & PCBs and SAMSUNG Korea made QLs & PCBs is very easy:
1. THORN (EMI) DATATECH QLs all have serial numbers starting with a D (for Datatech). Known build standards are D02 to D16. Most likely there was also a D01. The only reference for a D17 build standard is in an article in one specific QL World magazine. It could be a typo.
2. THORN (EMI) DATATECH QLs all have PCBs with naming ISS.x where x is the issue number. Known issue numbers are 2 and 4 to 7. Most likely there were also a 1 and 3.
3. SAMSUNG QLs all have serial numbers starting with a S (for SAMSUNG). Known build standards are S13 (The North American edition) and SG18 (the German edition). It looks like S13 started as a fork of D13, but evolved to a motherboard much closer to D14-D17. It looks like SG18 started after the D16 and, if ever existed, the D17 build standards.
4. SAMSUNG QLs all have PCBs with naming USx where x is the issue number. Known issue numbers are 3, 5, 5.1, 5.2, 5.3, 6. Even the earliest one of those is at least based on the UK made ISS.6 PCB. In other words, all US PCBs have the IC38 (HAL16L8). US stands for USA and indicates that the design targeted to comply with the US FCC regulations. Because Germany had their VDE regulations which were much stronger to the UK ones in the mid-80s, the FCC compliant US PCBs were good enough for the German edition of the QL.
A picture is telling more than 1000 words. Hence see this picture gallery:http://www.sinclairql.net/pic/Index.php ... RmNWI3ZTIw