27-09-2018, 02:12 AM
The TBA will have been there for its balanced modulators, which will encode as cheerfully as they will decode. Probably cheaper (and possibly requiring a lower component count) than two MC1496s.
At a rough guess, the 7493 is the colour bars generator. This is a ripple-counter, but it seems to be only capable of counting up, which would account for the reversed order of the colour bars. Knowing how Manor Supplies used to work, they'll probably have bought a few thousand of them for coppers each at a disposal sale, and cast around for something they could use them in that would sell. What is slightly surprising is that, having put some 7400s in the design, they didn't put another one in with the gates strapped as NOTs.
Some of their designs were... I think the polite word is probably "idiosyncratic", at best. In their defence, however, I ought to point out that their test gear largely did what it was intended to, and was targeted at a market for whom "official" kit would be prohibitively expensive. I wonder what the cost of, say, the Labgear colour bars generator was in 1976?
(One of their later colour bars generators was actually designed by a former colleague. That one used a Ferranti SPG chip, and an Astec modulator, so you got proper syncs, and tone as well, I believe. The subcarrier oscillator free-ran, so not math PAL, unfortunately).
At a rough guess, the 7493 is the colour bars generator. This is a ripple-counter, but it seems to be only capable of counting up, which would account for the reversed order of the colour bars. Knowing how Manor Supplies used to work, they'll probably have bought a few thousand of them for coppers each at a disposal sale, and cast around for something they could use them in that would sell. What is slightly surprising is that, having put some 7400s in the design, they didn't put another one in with the gates strapped as NOTs.
Some of their designs were... I think the polite word is probably "idiosyncratic", at best. In their defence, however, I ought to point out that their test gear largely did what it was intended to, and was targeted at a market for whom "official" kit would be prohibitively expensive. I wonder what the cost of, say, the Labgear colour bars generator was in 1976?
(One of their later colour bars generators was actually designed by a former colleague. That one used a Ferranti SPG chip, and an Astec modulator, so you got proper syncs, and tone as well, I believe. The subcarrier oscillator free-ran, so not math PAL, unfortunately).
There is hardly anything in the world that some man cannot make a little worse and sell a little cheaper, and the people who consider price only are this man's lawful prey.
John Ruskin
John Ruskin
