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=== Speed === | |||
Due to the fact that the different bits take different time on tape, the Spectrum's tape routine does not have a well-defined speed. We can calculate some limits and typical values though; as noted above, a '0' bit takes 2 × 855 = 1710 T-states and a '1' bit takes 2 × 1710 = 3420 T-states. Assuming a 48K Spectrum which runs at 3.50 MHz (the 128K machines run at 3.54 MHz or about 1% faster; that difference is largely irrelevant here), this means: | |||
* A stream of pure '0' bits loads at 3500000 ÷ 1710 ≈ 2046 baud | |||
* A stream of pure '1' bits loads at 3500000 ÷ 3420 ≈ 1023 baud | |||
* A mixed stream with equal numbers of '0' and '1' bits loads at 2 × 3500000 ÷ (3420 + 1710) ≈ 1364 baud | |||
Real world Spectrum data tended to have more '0' bits than '1' bits, so the typical baud rate was actually a bit higher than 1364 baud. | |||
== Blocks == | == Blocks == |
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