Polaris Service Manual: Options
The Polaris supports two types of RAM chips, 6116's or 6264's. A Polaris is usually delivered from factory to dealer with eight 6116 2K x 8 RAM chips installed, equal to 16K.
Optional memory packages are available for field installation to expand RAM, providing an increase in available note storage for the on-board sequencer. Two packages are available: Memory Expansion Package I, or Package II. Package I consists of four 6264 8K x 8 RAM chips, expanding RAM to 32K. Package II consists of two 6264 8K x 8 RAM chips, expanding RAM another 16K, to 48K. Adding a second Package II will expand RAM to 64K. Refer to "Memory Array" in section 3 of this manual for a more detailed description of configurations allowed.
The following is a copy of the installation instructions for the memory expansion kits:
Polaris Memory Expansion Package Installation Instructions
Part Number 309006401
- P/N 306864000 Mem. Expan. Pkg. I or 306801901 Mem. Expan. Pkg. II
- Cassette Recorder/Player w/tape
- I.C. insertion/extraction tool - hand tools
Make sure you save the customer's programs and sequences on cassette before you begin. This procedure will erase all programs and sequences from memory. Observe standard safety procedures for static sensitive IC's.
- Save the programs and sequences on cassette.
- Disconnect line power and open the Polaris.
- Remove the keyboard. CAUTION watch for keyboard spacer shims.
- Disconnect J15 from the main board. It is not sufficient to remove a battery from the holder, as the capacitor on the holder retains its charge for a rather long time.
- Using the correct extraction tool, remove the 8, 6116, 2K x 8 RAM chips from sockets Z2 through Z9.
- Using an insertion tool, carefully install 4, 6264, 8K x 8 RAM chips into sockets Z2, Z3, Z4, and Z5. Sockets Z6, Z7, Z8 and Z9 remain blank. This expands the memory from 16K to 32K and increases the sequencer note storage by 2700 notes. This conforms to the P/N 306864000 expansion package I.
- For one P/N 306801901 expansion package II kit, install 2, 6264, 8K x 8, RAM chips into sockets Z6 and Z7. Sockets Z8 and Z9 remain blank. This expands memory from 32K to 48K and increases note storage by another 2700 notes.
- For an additional P/N 306801901 expansion package II kit, simply install 2, 6264, 8K x 8 RAM chips into the remaining 2 sockets, Z8 and Z9. This expands memory from 48K to 64K and increases note capacity by 2700 more notes for an overall net increase of 8100 notes. Total capacity depends on program allocation to memory, but with a full 132 programs, capacity equals 8750 notes. With 50 programs, in excess of 9400 notes.
- Reverse both jumpers between Z8 and Z9. The jumper closest to pin 14 of Z9 should now be shorting the center pin to the pin on its right and the jumper closest to pin 15 of Z9 should short its center pin to the top pin. The write strobes and address bits are changed by these jumpers to conform to the type [of] memory chip in use.
- Reconnect the battery connector J15.
- Carefully align the keyboard and reassemble the Polaris.
- Perform software adjustments as outlined in "WHAT TO DO IF YOU LOSE YOUR MEMORY".
- Load programs and sequences.
The system supports two types of EPROM chips, 2764'3 and 27128's, allowing four configurations up to 64K ROM. The jumper located near the left rear corner of the main board (next to C819 and Z19) determines the addressing. This jumper should be shorting the center pin to the bottom pin (bottom is nearest keyboard) for 2764's. If 27128's are installed the jumper should short the center pin to the top pin. Refer to "Memory Array" in section 3 of this manual for a detailed description of allowable configurations.
One of the chief advantages EPROM'S provide, is the relatively easy means of updating certain characteristics of the system by changing them to a different software revision. As stated in Section 3, it is important to realize that when you change to a different revision the memory locations used for different purposes usually change. This means you have to reload all programs and sequences, implement a "scratch program", then perform all software adjustments outlined by "What to do if you lose your memory" in Section 6 of this manual.
There are five 3-pin and one 16-pin jumper connectors on the main board. Three of the 3-pin jumpers deal with memory chips (covered earlier in this section) but all will be described under this one sub-title to provide easy reference.
No reference designations exist for any of the six jumper connectors, but they are relatively easy to locate using adjacent components. References are defined as follows: Top, away from keyboard. Bottom, closest to keyboard. Left, right, viewing over keyboard onto main board. Top synonymous with rear, bottom synonymous with front.
One of the 3-pin jumper connectors, located near the left rear corner of the main board (next to C819 and Z19), determines addressing of the EPROM'S. The jumper should be shorting the center pin to the bottom pin for type 2764 EPROM'S. Type 27128 EPROM'S (or mixed 2764's and 27128's) require the jumper to short the center pin to the top pin.
Two 3-pin jumper connectors, located between RAM chips Z8 and Z9, steer the write strobes and address bits to conform to the type of RAM chip used. With type 6116 RAM chips the jumper closest to pin 14 of Z9 should short the center pin to the left pin and the jumper closest to pin 15 of Z9 should short the center pin to the bottom pin. With type 6264 RAM chips both pins must be reversed.
As described in Section 3, the Polaris uses either a 6 or 8 Mhz clock, derived from either 12 or 16Mhz, for the 80186-6 or 80186-3, respectively. Two 3-pin jumper connectors, reconfigure signal inputs for the two individual modes. In the 6Mhz version, the jumper adjacent to C884 and Z84 must short the center pin to the the bottom pin, while the jumper adjacent to C829 and Z29, short the center pin to the right pin. In the 8Mhz version, both pins must be reversed.
Next to C883 and Z83 is a 16 pin jumper platform. This was used for reconfiguring interrupt and DHA requests during development. Shorting jumpers should be installed to short pin 1 to 2, 3 to 4, 6 to 7, 10 to 11 and 14 to 15.