- #Trs 80 serial terminal program install#
- #Trs 80 serial terminal program serial#
- #Trs 80 serial terminal program software#
- #Trs 80 serial terminal program professional#
These were sold as master and slave drives, with the master hard disk (which had the resistor pack) needing to be the last one on the chain. Hard disks offered for the Model II also used a terminating resistor pack. It proved to be problematic since customers who lost their resistor packs could not use their machine (Radio Shack sold replacement packs for $50) and Model IIs sold from 1981 onward used a different floppy controller that did not require it.
#Trs 80 serial terminal program install#
This unusual setup was chosen so the user would not have to remove the cover and install or remove a terminating resistor pack on the floppy drive every time they wanted to remove or attach external disk drives. The external resistor pack worked by looping back the I/O lines on the external floppy connector to the SA-800 drive's terminator pins. The first revision models (1979–80) could not boot from a hard disk and the floppy controller required a terminating resistor pack for the last drive on the chain in place of the standard method of putting a terminating resistor pack on the internal disk drives. There were several hardware revisions to the Model II over its lifespan. If the user installed a double sided drive, they could get 1MB of space, however this required a modified DOS and Radio Shack did not officially support the use of double sided drives on the Model II. The disk format on the Model II closely followed the IBM 3740 standard, which specified 77 tracks, 26 sectors per track, soft sector formatting, and a sector size of 128 bytes for a formatted capacity of about 250k, however the Model II had a double density controller, so the disk format used 256 byte sectors and formatted capacity was about 492k. A later version of the keyboard was made by Cherry Corporation, but still used the capacitive technology rather than the more well-known Cherry mechanical keyswitches. Like most capacitive keyboards, it utilized a key mechanism with foam rubber disks these are prone to dry-rotting with age and requiring replacement. The keyboard was a capacitive keyboard made by Keytronic Corporation. CDC drives were used for the floppy expansion module. Like with the Model I/III/IV, boot disks on the Model II required Track 0 to be single density. The floppy controller in the Model II was a double-density, soft-sector unit based on the WD 1791 floppy controller. The floppy drive included with the Model II was a Shugart SA-800 full-height, single-sided 8" drive like most such drives, it spun continuously whether the disk was being accessed or not and the spindle motor was powered directly off the A/C line.
#Trs 80 serial terminal program serial#
Three internal expansion slots could be used for add-on cards such as additional serial ports and a video board that allowed bitmap graphics. Unlike the Model I/III, the Model II's memory map is compatible with standard CP/M-80. This was somewhat mitigated by the availability of the CP/M operating system for the Model II from third parties such as Pickles & Trout.
#Trs 80 serial terminal program software#
The different disk format and system architecture made it impossible to run Model I/III software on the Model II, thus it never had as much available. The Model II ran the TRSDOS operating system (renamed to TRSDOS-II starting with version 4.0) and BASIC. Because of this and the use of port I/O, almost all of the Model II's memory could be used by software.
![trs-80 serial terminal program trs-80 serial terminal program](https://cdn.arstechnica.net/wp-content/uploads/2015/07/DPP_0002-e1438360796307-640x207.jpg)
Unlike most computers, it had no BIOS ROM except a small boot loader (the BIOS was loaded off the boot floppy). The video memory could be banked out, so that the entire 64K address space could be used for main memory. It sported 80x25 text and a single-sided 500k 8" floppy drive, and either 32 or 64k of RAM, along with two RS-232 ports and a Centronics-standard parallel port.
![trs-80 serial terminal program trs-80 serial terminal program](https://3.bp.blogspot.com/-Cz9wyFN1tWw/WYP883YtLxI/AAAAAAAGV4A/Pvc38qOM7HcSQPXVWV6I7-f1HaiPtD9tgCKgBGAs/s1600/20170728_143920.jpg)
#Trs 80 serial terminal program professional#
Hardware Īs a professional business machine, the Model II used state-of-the-art hardware and had numerous features not found in the primitive Model I such as the high-speed (for the time) 4 MHz Z80A, DMA, vectored interrupts, a detachable keyboard with two function keys and numeric keypad, and port instead of memory-mapped I/O. The base single disk version was $3450, and a four disk version was $6599. It claimed that the computer was "ideal for a small business, and also 'just right' for many time-consuming jobs within larger businesses", including those with mainframes or minicomputers. Tandy advertised the Model II as "a business computer - not a hobby, 'home' or personal computer". It was announced in May 1979, deliveries began in October, and only Tandy-owned Radio Shack stores sold the computer. The computer was too limited for such use, so the company began development on the Model II in late 1978.
![trs-80 serial terminal program trs-80 serial terminal program](https://www.trs-80.com/images/hardware/computer-model100x250.gif)
Tandy was surprised at the strong demand for the TRS-80 Model I from business purchasers.