************ ********* PLANET SHELEZYAKA
(C) Darth Vader / Triumph
Matching circuits Modem Spectrum'om
(Reproduced with modifications)
Copyright G. Shepelev
from the computer contacts the slot modem:
DATA 0-7 A9-A2 DATA 0-7
A15 555LL1
1
1 A22, A23 A9, A8
A14 O
A24, A25 A7, A6
A13, A12 10k
+5 V IORD (B14)
RD 1> IOWR (B13)
LL1 November 13
March 1
A4 1 o
2 LL1
/ IORQ
1
/ WR o
K555TM2
+5 V 1 R Q 5
3 C
A11 2 D
/ RESET o 4 S
1 RESDRW (B2)
K555LN1
1 / NMI
IRQ4 (B24) 1
MODEM
A8 A0 (A31)
By A9 A1 (A30)
On the A10 A2 (A29)
M
N D0-D7 D0-D7 (A9) - (A2)
on the +5 v 10K A3-A10 (A28) - (A21)
GND AEN (A11)
Used K555LL1, K555TM2 and K55LN1.
Do not forget to bring power to the modem and Wrotham
to set the jumpers on the modem and COM1 IORQ4.
-5v - B5-12v-B7
+5 V - B3, B29 +12 v-B9
GND - B1, B10, B31
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Matching circuits Modem Spectrum'om
(A modified version of the scheme M. Kondrateva)
LL1
__ 12> IORD (B14)
RD 1> IOWR (B13)
LL1 November 13
March 1 __
A4 1 o __ o> IORQ4 (B24)
____ 2 LL1 LA3
IORQ o 4 6 4
TM2 1 o '6
__ 5 1 5 o
WR +5 B> oR 6
2 o
A11 D
March 1 LP8
/ C o o 3
___ 4 5 2
RES o oS
5 LP8
LA3 +5 V> o o 6
4 ___ 4
o '6 ___ o o
5 o LP8
12
11
__ 13
M1 o
D1
___
INT
> RESET (B2)
+5 B>> to vyv.14 chips LL1, LA3, TM2, LP8
> To vyv.7 chips LL1, LA3, TM2, LP8
In parentheses are pin numbers on the modem board. On the
left the signals connected to the Speccy, and to the right to
the modem.
Products: 555LL1, 555LA3, 555TM2, 555LP8.
Resistors: 1k
Refinement scheme Spectrum
~~~~~~~~~~~~~~~~~~~~~~~~~~
Z80
cut
___
x INT
___
|___|
/ 560
add
___
> INT
Wiring diagram for Spectrum'u
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Modem System
port
_____ __________
| A 8 |----> | a31 | A 0 |
| A 9 |----> | a30 | A 1 |
| A10 |----> | a29 | A 2 |
| D 0 |----> | a9 | D 0 |
| D 1 |----> | a8 | D 1 |
| D 2 |----> | a7 | D 2 |
| D 3 |----> | a6 | D 3 |
| D 4 |----> | a5 | D 4 |
| D 5 |----> | a4 | D 5 |
| D 6 |----> | a3 | D 6 |
| D 7 |----> | a2 | D 7 |
| | | A28 | A 3 | -
| | | A27 | A 4 | AT
| | | A26 | A 5 | +5 v
| | | A25 | A 6 | a
| | | A24 | A 7 | 3-10k
| | | A23 | A 8 |
| | | A22 | A 9 | -
| | | A21 | A10 | - on the ground
| | | A11 | AEN | - on the ground
| | | B9 | +12 v | to the corresponding IP | | | b7 |-12v |>
source of stress | | | B |-5v | / modem if required
| GND |----> | b1 | GND |
| GND |----> | b31 | GND |
| +5 V |----> | b3 | +5 v |
| RESET | - by - | b2 | RESET |
| RD | - | b13 | IOWR |
| A4 | - n | b14 | IORD |
| IORQ | - L | b24 | IORQ4 |
| WR | - a | | |
| A11 | - T | | |
| INT | - y | | |
| _D1__ | - |__________|
signal signal
Unlike the scheme of the prototype in the process of issuing
interrupts to the computer. Because possible alter ROM we
nebylo, we decided to use the normal INT, rather than NMI.
Interrupt processing is performed in the mode of IM2. It should
be noted that the issue interrupt to the computer from the
modem is accompanied by change the interrupt vector that is
easily tracked in the mode of IM2. Thus retained the ability to
work with interrupts coming from the computer.
No other differences and programs that do not use the same
interrupt from the modem will work on any option scheme.
