Congratulations for selecting this Radio Shack Computer product! The TRS-80 Expansion Interface greatly enhances the power and usefulness of your LEVEL II TRS-80 Computer. With it, you can connect a wide variety of external components ("peripherals") to your Computer - printers, mass storage devices, communications equipment, voice synthesizers, speech recognition devices, custom-made I/O devices, etc.
Contents SETTING UP Installing the Power Supplies .. . . . . . . . . . . . . . . . . . . . . . . . 3 Cables, Card-Edges and JaGks , 4 Connection to the TRS-80 ; . . .. 6 Power-Up and Notes 8 10 Adding RAM PERIPHERALS Dual Cassettes Line Printer Mini-Disk(s) 12 , 14 16 Bus~ompatible Devices . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16 Expansion Board 16 TECHNICAL INFORMATION 25 mS Heartbeat Interrupt . . . . . . . . . . . . . . . . . . . . . . . . .. Floppy Disk Controller IC ... . . . . . . .
SETTING UP Installing the Power Supplies The Expansion Interface contains a storage compartment for two Power Supplies - one for the Interface, the other for the TRS-80 Computer. Keeping the Supplies inside this Compartment saves space and makes the System more "manageable". 1. The entire system should be OFF and both Power Supplies unplugged. 2. Remove the three phillips-head screws from the Power Supply Compartment cover (see Figure 1). 3.
SETTING UP Cables, Card-Edges and Jacks Figure 2 shows the Expansion Interface with the connection cables supplied with the unit. Figure 2. Expansion Interface with cables supplied. You also receive connector hoods for all the card-edges, including the one on the left rear of your TRS-80. Be sure to use the hoods for the cable connectors. They act as keyways to help you to avoid the misalignment of pins.
SETTING UP Figure 4 identifies the various card-edges and jacks. Note that the card-edges are concealed behind protective cover-plates. Don't remove a cover unless you plan to use that card-edge. To remove a cover-plate: press in on the right side of the plate until it pivots slightly. Then grasp the left side of the plate and pull out. (FRONT VIEW) TR5-S0 INTERFACE CARD EDGE TR5-S0 BUS EXTENSION CARD EDGE (REAR VIEW) TRs-BO CASSETTE - I/O JACK Figure 4. Card-edge and jack location.
SETTING UP Connection to the TRS-80 1. Position the TRS-80 as illustrated (Figure 5, rear view). Lift the door covering the Expansion Card-Edge, and slide it slightly to the right, then lift it up and away from the TRS-80 (be careful not to break the little plastic tabs). REMOVE DOOR OVER TRS-BO EXPANSION CARD EDGE I CONNECTOR AND CABLE Figure 5. Connection to the TRS-aO. 2.
SETTING UP 5. Position the Expansion Interface behind the TRS-80 keyboard and place the Video Display on top of the Expansion Interface, taking care that the "feet" on the Display lock into the recesses on top of the Expansion Interface case (Figure 7). Figure 7. Set up your TRS-aO/Expansion InterfaceNideo Display system this way.
SETTING UP Power-Up and Notes With the Expansion Interface connected to the TRS-80 Computer as explained in the last section, you are ready to tum on the components. Note: If you are going to connect any peripherals, do it while the system is OFF (see Peripheral Connection). Never change the connections to the Expansion Interface or Computer while the Computer or Interface is ON. 1. Make all connections before you plug in the AC line cords. 2. Tum on the peripherals you are going to use. 3.
SETTING UP Notes on AC Power Sources Although your TRS-80 Micro-Computer system uses the latest in efficient, low-current electronic devices, it is important to avoid using household extension cords, multiple outlets or "cube-taps", etc. Place your TRS-80 system as close as possible to standard AC power outlets.
SETTING UP Adding RAM to the Expansion Interface Connecting your "no RAM" unit (26-1140) will not affect the total amount of memory in your system. Before adding RAM to your Expansion Interface, you must fill your TRS-80 with 16K RAM. Then, when you need more memory, you have it added to the Expansion Interface in blocks of 16K, for a total of up to 32K in the Interface, or a system total of up to 48K. Preserve your Warranty - let Radio shack install and test all additional RAM in your Interface.
PERIPHERALS Refer to Figures 2, 3 and 4 while connecting any peripheral equipment.
PERIPHERALS Dual Cassettes By adding a second cassette recorder to your system, you'll be able to speed up your cassette input/output operations. For example, you can read a program or data from one recorder, edit the program or update the data, and write it out to the other recorder - no need to swap cassettes, rewind or reset Play and Record keys ... ! Note: If you have just one recorder, leave it connected directly to the CASSETTE jack on the TRS-80.
PERIPHERALS Dual Cassette Operation LEVEL II BASIC To select a cassette drive with LEVEL II BASIC, use the following statements (see the LEVEL II BASIC Reference Manual for details): CLOAD#-l,filename Loads a program from Cassette I CLOAD#-2,filename Loads a program from Cassette 2 Note: ,filename is optional - omit if you want to load the first program encountered on the tape.
PERIPHERALS Line Printer The Line Printer Card Edge provides a parallel data interface which is compatible with Radio Shack Line Printers. The connection cable and instructions will be supplied with the Line Printer. Use with Other Printers Certain other line printers can be connected to the Line Printer Card Edge. In general, the Printer must: 1. Be equipped with a female 34-pin connector to mate with the Expansion Interface card-edge. 2. Accept 7- or 8-bit ASCII data in parallel format. 3.
PERIPHERALS Line Printer Output LEVEL II BASIC There are two statements for output to the Line Printer, LPRINT and LUST. See the LEVEL II BASIC Reference Manual for details. Note: If you don't have a line printer connected, LPRINT and LUST will cause your Computer to lock up, requiring you to Reset it. (Hold down BREAK while you press Reset.) Resetting the Computer with the Expansion Interface connected will cause you to lose any BASIC program in memory.
PERIPHERALS Mini Disk(s) Connect one 26-1160 Mini Disk Drive and up to three additional 26-1161 Mini Disk Drives, as explained in the Mini-Disk Operation Manual. The connection cable is supplied with 26-1160. Attach one of the flat connector hoods to the Mini-Disk connector before attaching it to the Expansion Interface Card Edge. The ribbon cable should exit from the bottom of the hood. Bus Compatible Devices This card-edge provides required signals for additional Radio Shack peripherals.
PERIPHERALS Expansion Board Installation To expose the Expansion Compartment, remove the four phillipshead screws from the Cover and lift it off (Figure 9). Notice the connector inside the compartment; this will connect to your add-on board. Figure 10 gives the required dimensions for a do-it-yourself board to fit in the Expansion Compartment and connect to the Expansion Connector. ~ ..v HOUSING FOR FUTURE ~~ EXPANSION BOARD EXPANSION INTERFACE Figure 9.
PERIPHERALS .188 DIA.(3/16) CENTERLINE PIN 1 .165 .150 2.350 41 SPACES @ .050=2.050 .125 DIA.(1/8) 6.375 MAX. VIEWED FROM SIDE OPPOSITE COMPONENTS ---..I 1.78~ .160 NOTES 2.900 UNLESS OTHERWISE SPECIFIED: 1. MAXIMUM COMPONENT HEIGHT .660 ...- - - - - - 5.688 MAX. ---------J~ Figure 10. Expansion Board required dimensions. 18 B>MAXIMUM COMPONENT HEIGHT 1.
TECHNICAL INFORMATION 19
TECHNICAL INFORMATION 25 mS Heartbeat Interrupt A clock circuit in the Expansion Interface provides an Interrupt to the Z-80, 40 times each second. When such an Interrupt is received, the Z-80 gets instructions from ROM telling it to go to a specific RAM address for further instructions. Normally, these "further instructions" simply tell the Z-80 to return from the interrupt sequence and continue where it left off.
TECHNICAL INFORMATION 50 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 REM •.
TECHNICAL INFORMATION Assembly-language programmers can use the following listing to relocate the real-time clock code.
TECHNICAL INFORMATION (Real-Time Clock Code, continued) XIT FDC INC INC LD CP JR XOR LD INC INC LD CP JR XOR LD LD HL (HL) A, (IlL) POINT TO MINUTES AND INCREMENT ; GET MINUTES COUNT 60 C,XIT A (HL) ,A HL (HL) A, (HL) 24 C,XIT ~HL) A A,(3~EOH) p8p ilE MT A, (37ECH) ~~D OS~ DONE IF NO CARRY ELSE RESET MINUTES POINT TO HOURS AND UPDATE GET HOURS 24-HOUR CLOCK DONE IF NO CARRY ELSE RESET HOURS TO RESET LATCH RESTORE REGS AND EXIT ENABLE INTERRUPTS RESET FDC IRQ RQST 23
TECHNICAL INFORMATION Floppy Disk Controller IC The Floppy Disk Controller (FDC) in the Expansion Interface directly controls the drive motors; track stepping and direction; write gating and data. It also inputs information on the diskette index position, track zero occurrence, write protection and data/clocking all at the Mini Disk Card-Edge on the Expansion Interface. The FDC registers (CMD/STATUS, TRACK, SECTOR, DATA) are located at TRS-80 memory addresses 37ECH, 37EDH, 37EEH and 37EFH, respectively.
TECHNICAL INFORMATION Address Decoding Scheme The Address Decoder logic consists of Z43, Z40, Z39 and one inverter from Z32. Z40 is a dual 2-line to 4-line demultiplexer. One half of this package selects 16K increments of RAM. The input signals to this section are MRAS*, Al4 and AIS. MRAS* serves as a valid memory address signal; a logical f/J indicates that the addresses have stabilized. Table 1 summarizes the I/O combinations.
TECHNICAL INFORMATION Cassette Jack Signals These jacks allow connection and control of a pair of Cassette Recorders via the Expansion Interface. The pinouts for the three jacks are the same. 4 2 '~' PIN 1 2 3 4 5 SIGNAL NAME MOTOR ON/OFF GROUND MOTOR ON/OFF CASSIN CASSOUT DESCRIPTION Allows TRS-80 to control tape motion. Signal Ground. Allows TRS-80 to control tape motion. Allows taped programs to be loaded into the TRS-80. Allows cassette recorder to record programs from the IRS-80 onto tape.
TECHNICAL INFORMATION Note: CASSOUT A and B are both used to produce the cassette audio signal, as follows: CASSOUT A B Audio Pulse High 0 0 No Signal I I Pulse Low 0 I Pulse Low I 0 Pulse High O.85V No Signal 0,46V Low O.OV Table 5. How CASSOUT A and B produce the three-state cassette audio (High, Low, No Signal).
Line Printer Card-Edge Signals SIGNAL NAME PIN DESCRIPTION DATA STROBE* 2 GND 3 4 5 Dl GND D2 GND D3 GND D4 GND D5 GND DB GND 6 7 8 9 10 11 12 13 14 15 16 17 18 A 1.0 microsecond pulse used to clock the data from the processor to the printer logic. Signal Ground Input data levels. A high represents a binary one, a low represents a zero. All printable characters (i.e., codes having a one in DATA 6 or DATA 7) are stored in the printer buffer. Control characters (i.e.
Mini Disk Card-Edge Signals SIGNAL NAME PIN DESCRIPTION Signal Ground Not Connected Signal Ground Not Connected Signal Ground Not Connected Signal Ground Indicates the physical beginn ing of a track. Signal Ground When active, locks the mini-disk RIW head against the mini-diskette (disk drive no. 0). Signal Ground When active, locks the mini-disk RIW head against the mini-diskette (disk drive no. 1). Signal Ground When active, locks the mini-disk RIW head against the mini-diskette (disk drive no. 2).
Bus Card-Edge Signals This card edge duplicates the card edge on the TRS-80 Computer. SIGNAL NAME PIN RAS* SYSRES* 1 2 3 4 5 6 7 8 9 NC A10 A12 A13 A15 GND All A14 A8 OUT* WR* INTAK* RD* NC A9 D4 IN* D7 INT* Dl TEST* 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 D6 A0 D3 Al D5 GND D0 A4 D2 WAIT* A3 A5 A7 GND A6 +5V A2 33 34 35 36 37 38 39 40 NOTE: DESCRIPTION Row Address Strobe Output for 16-Pin Dynamic Rams.
TECHNICAL INFORMATION Expansion Board Card-Edge Signals If you install an expansion board in the Expansion Compartment, this Card-Edge will give you easy access to the added board. For example, with the Radio Shack RS-232C Serial Interface installed, you will connect your external RS-232C equipment to this CardEdge.
Expansion Board Card-Edge Signals (RS-232C Installed) *SIGNAL NAME PIN DEseR IPTION Signal Ground GND NC GND NC GND NC GND NC GND 1 2 3 4 5 6 7 8 9 Signal Ground Signal Ground Signal Ground Signal Ground Internal Expansion Connector - Pin 16 (not used). Signal Ground I nternal Expansion Connector Pin 15 (not used). Signal Ground Internal Expansion Connector - Pin 14 (not used). Signal Ground Protective Ground Signal Ground Transmit Data - Signals on this Circuit are sent to remote Equipment.
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LIMITED WARRANTY For a period of 90 days from the date of delivery, Radio Shack warrants to the original purchaser that the computer hardware described herein shall be free from defects in material and workmanship under normal use and service. This warranty is only applicable to purchases from Radio Shack company-owned retail outlets and through duly authorized franchisees and dealers. The warranty shall be void if this unit's case or cabinet is opened or if the unit is altered or modified.
