Instruction manual

A Warning:
The MACAOTEA™
is for Professional
Programmers -
and Very
Serious Amateurs - Only
An Additional 1/0 Interface
for the PET
Interfacing a VIA 6522 to your PET is simple.
ASSEMBLE LIST
0100 :MOVE TBl 1 TO TBl2
0110 . BA $400
0400- AI
0B
0120
lOOP lOY #00
0402- B9 0B
Q)4
0130 lOA
TBl1.Y
0405- 89 0B Ql5 0140
STA
TBl2,Y
0408- C8
0150 INY
0409 OQl F7 0160
BNf
LOOP
0170
Q)40B
Ql180 TBU .OS 256
050B
019Ql TBl2 . OS 256
0200
0210
EN
lABEL FilE 1 = EXTERNAL
START =
0400 lOOP = 0402
TBl2 =050B
110000.050B,051'lB
VISA, Mastercharge orders call (BOO) 227-8398 (Except Calif.)
@l California orders please call [phone].
o ~~!~~D"~~~~O~~~4'~~~~S
TBl1 = 04UJB
To create a tone on CB2 for the cir-
cuit in figure
1;
POKE 32763, 16 (ACR)
POKE 32762, 15 (SR)
POKE 32760, 155 (Timer 2) for the
circuit in figure 2.
POKE 32747, 16 (ACR)
POKE 32746,
15 (SR)
POKE 32744, 155 (Timer 2)
For further specs. on the "PB" port of
the 6522, refer to the 6522 data sheet.
Kevin Erler
P.O. Box 3032
Edson, Alberta TOE OPO
Canada
shown in figure
1)
32752 - ORB
32753 - ORA
32754 - DDRB
32755 -
DORA
32756 - TIL-L TIC-L
32757 - TIC - H
32758 - TIL-L
32759 . TIL-H
32760· T2L-L T2C·L
32761 - T2C-H
32762 - SR
32763· ACR
32764 -
PCR
32765 - IFR
32766 - IER
32767 - ORA (no handshake)
The operation is as with other
VIA---
PEEK POKE etc., only with the previous-
ly listed addresses.
Note--for
the addresses which
operate the circuit in figure 2, simply
subtract
16 from each address.
Output Example
The Software
The Hardware
The 6522 VIA chip has a lot
of in-
teresting features, however, many
of
them are on the "PB"side of the chip.
The Commodore
PET does not have the
"PB" lines on its user port, only the
"PA" lines. The following interface gives
not only the wanted
"PS" lines but also
an extra set of "PA" lines &CB1, CB2,
CA1, & CA2.
The
circuit itself uses only a 6522
VIA and
two 74 i 1 'so It is mostly direct in·
terfacing, other than the address lines
which had to
be decoded. Once built, it
connects directly to the Memory Expan-
sion Port.
The interface (in figure
1) is design-
ed to occupy the top 16 bytes of RAM. It
should
be noted here that adding
another interface is as simple as chang-
ing the address decode. For example, by
placing
an inverter on "BA4" (see figure
2)the
circuit would occupy the 16 bytes
of
RAM just under the top 16 bytes.
(note-if you build both of the
circuits
from figures 1 & 2 you would have two
VIA's and would
be using the top 32
bytes of RAM). The original circuit is
shown in figure
1.
After connecting it, operation is
very simple. The addresses concerned
and
what they are follows. (for the circuit
Now: a machine language pro-
gramming powerhouse for the
knowledgeable programmer who
wants to extend the
PET's capa-
bilities to the maximum. The
MacroTeA, the Relocating Macro
Text Editor.Assembler from Skyles
Electric
Works.
The Skyles MacroTeA is a super
power1ul text editor. 26 powerful
editing commands. String search and
replace capability. Manuscript feature
for letters and other text. Text loading
and storage on tape or discs. Supports
tape drives, discs,
CRT, printers and
keyboard.
The Skyles MacroTeA is a relocating
machine language assembler with true
macro capabilities. A single name
identifies a whole body of lines.
You
write in big chunks, examine, modify
and assemble the complete program.
And, when loading, the MacroTeA goes
where
you want it to go. Macro and
Gonditional assembly support. Auto-
matic line numbering. Labels up to 10
characters long.
The Skyles MacroTeA is an enhance
Monitor.
11 powerful commands to
ease you past the rough spots of
program debugging.
The Skyles MacroTeA is a wann
start button. Over
1700 bytes of
protected
RAM memory for your object
code.
There's no tape loading and no
occupying of valuable
RAM memory
space:
The Skyles MacroTeA puts 10K
bytes of executable machine language
code in ROM (from 9800 to BFFF-
directly below the BASIC interpreter).
2K bytes of RAM (9000 to 97FF).
Like all Skyles Products for the PET, it's practically plug in
and go. No tools are needed. And, faster than loading
an
equivalent size assemblerleditor from tape, the MacroTeA is
installed permanently.
The Skyles MacroTeA: 13 chips on a single PCB. Operates
interfaced with the PET's parallel address and data bus
or with
the Skyles Memory Connector.
(When ordering, indicate if the
MacroTeA will interface with a Skyles Memory Expansion
System.
You can save $20.) Specifications and engineering are
up to the proven Skyles quality standards. FUlly warranted for 90
days. And, as with all Skyles products, fUlly and intelligently
documented.