Macintosh Classic II Memory Upgrade Guide
The Macintosh Classic II (and the Performa 200, which is the same machine) has 2 MB of RAM soldered to the logic board and two 30-pin SIMM sockets on the board itself. The maximum is 10 MB.[1]
Memory specifications
[edit | edit source]- On board: 2 MB soldered.[1]
- Sockets: two 30-pin SIMM connectors on the logic board.[1]
- Speed: 120 ns or faster.[1]
- Fitted in pairs. The Classic II has a 16-bit external data bus; the two sockets are filled together or left empty together.[1][2]
- Eight-chip, non-parity modules. High-density two- or four-chip modules are not detected correctly.
- Maximum: 10 MB — 2 MB on board plus a pair of 4 MB SIMMs.[1]
Supported configurations
[edit | edit source]| Total RAM | SIMM 1 | SIMM 2 |
|---|---|---|
| 2 MB | — | — |
| 4 MB | 1 MB | 1 MB |
| 10 MB | 4 MB | 4 MB |
A pair of 2 MB SIMMs gives 6 MB where the modules are genuine 30-pin 2 MB parts, but 1 MB and 4 MB are the sizes Apple's configurations are built around.
Tools
[edit | edit source]- Long T15 Torx screwdriver (at least 150 mm / 6 in)
- Case separator or plastic spudger
- Anti-static wriststrap
- A matched pair of 30-pin SIMMs
See Recommended Tools.
Procedure
[edit | edit source]1. Prepare. Power off, unplug, work on a grounded surface.
2. Open the case. The Classic II contains a CRT. Read CRT Discharge Procedure first, discharge the CRT before disconnecting anything, and do not fit a grounding wriststrap until after it has been discharged.[1]
3. Withdraw the logic board to reach the sockets.
4. Fit the SIMMs as an identical pair: insert at an angle, then rotate down until the clips engage.
5. Check both modules are level and fully seated, reassemble, and verify the total in "About This Macintosh".
Common problems
[edit | edit source]| Symptom | Likely cause | Action |
|---|---|---|
| Sad Mac, or no video with a chime | One SIMM fitted, or two of different sizes | Fit an identical pair; reseat both |
| Reported total lower than expected | High-density two- or four-chip modules | Fit eight-chip modules |
| Random freezes | Dirty contacts, or modules slower than 120 ns | Clean contacts with isopropyl alcohol; use 120 ns or faster |
| Sad Mac after fitting memory | Parity modules | Use non-parity modules |
Apple's own Sad Mac chart for this machine says to replace the RAM SIMMs in the two logic board slots before replacing the logic board.[1] Codes are decoded on Sad Mac Error Codes and with the Sad Mac Decoder.
Related pages
[edit | edit source]- Macintosh Classic II
- Macintosh Classic / Classic II General Maintenance
- Macintosh Classic / Classic II Troubleshooting
- Apple Service Source
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Apple Computer, Macintosh Classic/Classic II/Performa 200 Service Source — Specifications (Memory) and Troubleshooting chapters. Hosted on this wiki: File:Classic ii.performa 200.pdf.
- ↑ Low End Mac, Mac Classic II tech specs (secondary source): 2 MB expandable to 10 MB using two 30-pin SIMMs; 16-bit data path; introduced 21 October 1991 at US$1,899, discontinued 13 September 1993; Performa 200 introduced 14 September 1992.