Raspberry Pi within a terminal super old

and in another unreleased episode of “are not going to stop until a Raspberry Pi prepare us a cappuccino» the plan is to combine the magic of the popular mini computer with an older terminal that this writing. After leaving sleep for a couple of years, the user «dennis1a4» took to its terminal Heathkit H-19A in 1980, he made some repairs, and connected it to a Raspberry Pi via its serial interface. The end result is much more «Fallout» than we can imagine.

terminals require more patience than a traditional computer. Modern software can largely emulate the best-known terminals, but if you plan to restore or reuse one, you should know well what you’re doing. My general knowledge is limited to keyboards of terminals, the conversion of its protocols and amendments that need to function properly in a current system. However, some enthusiastic beyond outside have time and ability that allows them to go beyond. A good example is the «dennis1a4» who rescued a terminal Heathkit H-19A waste (agosto de 1980) . Several years later, he decided to remove from its shelves and do something with it. The best option? Use it as a terminal for a Raspberry Pi .

the terminal with the Raspberry Pi hanging inside

to be a piece of hardware with more than three decades of age it is logical to expect some technical drawbacks. In this case, – 5 and – 12 volt lines were hors de combat. 7912 controller (-12v) is responsible for feeding the 7905 (-5v) so the early suspicions focused on the 7912, but its performance outside circuit was correct. To measure line – 12v discovered a short to Earth at some point. Fortunately, the first component removed turned out to be the culprit, an old capacitor at the exit of the 7912. Once replaced the capacitor and replaced the regulator, began to work on the rest of the terminal. Had echo of characters but nothing in the output, since it was in offline mode (la tecla que cambiaba el modo se averió).

with a couple of chips out, Raspberry Pi and the terminal are spoken without obstacles

and thus reach a conflict of voltages. Heathkit H-19A use +/-12v on the serial interface, with the potential to enlighten the Raspberry Pi as a Christmas tree. Once again, luck favored dennis1a4: the voltage on the line of data from the CPU to the serial interface chips was about 3 volts, therefore, the solution was to remove those chips, and connect the Raspberry Pi directly to the CPU of the terminal. The last step was to enable ANSI escape sequences, and configure the link 9,600 baud. The rest is history.

let your vote

0 points

Downvote Upvote

Total votes: 0

Upvotes: 0

Upvotes percentage: 0.000000%

Downvotes: 0

Downvotes percentage: 0.000000%

Be the first to comment

Leave a Reply