In late 1981 I built a computer around the Z80, TMS9918A (actually 9928A as I wanted PAL-M output) and the TMS5220 voice synthesis chips. I called it "Einstein"

In late 1981 I built a computer around the Z80, TMS9918A (actually 9928A as I wanted PAL-M output) and the TMS5220 voice synthesis chips. I called it "Einstein" and only found out decades later that there was a computer from Tatung with the same name, processor and video chip that sold in the UK in 1984. Great minds think alike, it seems... I was not able to get a datasheet for the 9918 and had to abandon the project. In early 1983 I did get a nice book from Texas Instruments by asking them to send it to an address in the US, but I only skimmed it. That was a huge mistake. A few months later I started a new computer project for the Logo programming language and remembered that Logo in the TI99/4 kept "running out of ink". There were only 256 different characters which could be redefined but the screen was 32x24 = 768 characters in size. So 2/3 of the screen had to be blank as the turtle moved around it. So I went with the Motorola 6883/6847 combo instead (the same as the TRS-80 Color Computer). It so happens that the TMS9918A used in the TI99/4A has a new mode that the TMS9918 didn't: you can divide the screen in 3 with a different character set for each part. That would have given me Logo with infinite ink.