Hardware - extension for PROFI for connecting other devices (T-Rex's Device 1.2)

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║ FERRUM for the PROFI computer ║
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║ Author: T-Rex/Power Of Sound Group ║
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   In this article I propose to expand
solution for PROFI (T-Rex's Device 1.2).
(I've had this on my car for a year now)
This extension allows you to connect
devices other than the computer
those given here.
  In mode (CP/M=1, ROM14=1) entered
port 123 (#7B):

           CONTROL BITS
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║ 0║ ║
║ 1║ Free for now ║
║ 2║ ║
║ 3║ ║
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║ 4║ 1-Disable writing to pseudo-ROM║
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║ 5║ ROM selection (00-main) ║
║ 6║ ║
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║ 7║ 1-Select pseudo-ROM ║
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  Pseudo-ROM is a part of RAM that
connects in place of a regular ROM.  And
works like a standard ROM. If necessary,
consumption of a memory area in RAM, where
located pswedoROM can be disabled,
if you write to port: 111*****, where
*- any value.
Pseudo-ROM is located in banks:
#08-CP/M loader
#09-TR-DOS
#0A-BASIC-128
#0B-BASIC-48
Naturally, you need to load something there
beforeconnecting pseudo-RAM instead
ROM.
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P.S. This extension has been tested on
PROFI 4.2, and if everything is drawn correctly
That's right, it most likely works.  It
was assembled "in haste" from the
microcircuits at hand, therefore
whoever wishes can minimize it.