But the development of the OS and BASIC did not go the way Sinclair expected. So Sinclair arranged for another OS to be developed. Because the combined size of the OS and BASIC was greater than intended, it did not fit in the 32K byte space that had been planned to be used. The first QLs were supplied with two 16K byte ROMs on the main board, with one 16K byte ROM in the dongle. A total of 48K bytes of ROM.
Sinclair could have fitted two 32k byte EPROM chips in the QL. On the issue 5 boards there are two sockets that can take a variety of different ROMs/EPROMs, but both have to be same type. Later a modification was done so that a 32K EPROM and a 16K EPROM could be fitted. The final ROMs were mask programmed ROM chips, one 32K bytes in size and one 16K bytes in size.
The intended memory map was this:
Code: Select all
FFFFF Reserved - expansion I/O C0000 Reserved - add on RAM 40000 Main RAM (96K bytes) 28000 Screen RAM (32K bytes) 20000 I/O devices 18000 Reserved (I/O devices) 10000 ROM cartridge slot (32K bytes) 08000 ROM (system ROM containing OS and SuperBASIC) (32K bytes) 00000
Code: Select all
FFFFF Reserved - expansion I/O C0000 Reserved - add on RAM 40000 Main RAM (96K bytes) 28000 Screen RAM (32K bytes) 20000 I/O devices 18000 Reserved (I/O devices) 10000 ROM cartridge slot (16K bytes) 0C000 ROM (system ROM containing OS and SuperBASIC) (48K bytes) 00000
I don't have an early version of the QL. They are rare, as Sinclair either replaced the whole machine or the PCBs after the owners returned the first QLs (Sinclair had a general recall for all the first QLs).
Anyway, a while ago, someone in the Retro community got hold of an early QL complete with dongle. They were expecting no end of problems when they powered it up. But to their surprise, it worked. They could load and run software off the microdrives. The machine was usable. See this QL Forum post.
You are right though that it was very common in the fledgling home computer industry for products to be late to market. In fact, this was not limited to the home computer industry, but was the typical way that a lot of small businesses operated.
That's why consumer TV programmes always advised viewers to be careful when ordering from mail order companies.
So the Vega+ / Retro computers is no different to any other company that has failed it's customers. That's not unique to the computer boom in the early 1980's in my opinion.
Sinclair may have got in trouble for late delivery of machines. But their customers did get a working machine eventually.