The 48GX is the expandable member of HP's 1993 G series: the same RPL calculator as the 48G, with four times the memory at 128 KB and two card slots on the back. Port 1 takes up to 128 KB that can merge with main memory, and slot 2 takes up to 4 MB in banks, for RAM cards or ROM cards of software. Dave Arnett of the design team said the processors that ran closest to 4 MHz went into the GX. It has the 48's serial port and infrared link, 3D plotting and HP's Equation Library. HP kept it in the line after the cheaper 48G+ arrived in 1998, and sold both until 2003. There was even a 1993 edition for the ASEE's centenary.
Good forEngineeringCollecting
Bench check
Should come with it
Check the listing photos against this list, and ask the seller about anything you can’t see. A missing piece should come off the price.
Few documented faults. Run the self-test, check any cards and their coin cells, and confirm it's a GX with slots.
New to old calculators? The condition checklist covers battery corrosion, displays, keys and card readers, and RPN in one hour gets you typing on an HP.
Buying guide
We'd buy the 48GX titled tested and working with its original case at $212 delivered, under the $230-340 band most working ones ask. There are at least 45 for sale, and kits with extras ask more, $440 delivered for one with its box and $565 for one with a Topcon survey card and 512K RAM. Check the photos show the slot cover on the back, since a 48G or 48G+ has no card slots, and ask for the ON and D self-test through to KBD1 OK. Skip the one titled Screen Issue unless the seller prices it as a repair.
$211.69est. delivered
The lowest delivered 48GX titled tested and working, at $212 with its original case in the photo. Ask for the KBD1 OK self-test result and a photo of the slot cover on the back.
HP 48GX 128K RAM Graphing Calculator Original Case Tested Working Vintage
$229.99delivered
Titled works great, at $230 delivered with free shipping from a 100% seller, at the bottom of the band. The seller lists a second one with the same title, so ask for photos of the unit you'll get.
Hewlett Packard HP 48GX 128K Graphing Calculator Works Great!
$309.77est. delivered
Titled bench tested and passing all diagnostics, with a case, at $310 delivered from a 99.5% seller, right at the median. Ask for a photo of the self-test it passed.
HP 48GX Calculator W/ Case - BENCH TESTED & Verified (Passes All Diagnostics)
Delivered prices include shipping as eBay quoted it to a US address on Oct 15, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Snapshot
Checked . Some may have sold.
Delivered prices include shipping as eBay quoted it to a US address on Oct 15, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Used$211.69est. delivered
$199.99 + $11.70 shipping
Buy It Now$199.99
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
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Good buy
Titled tested and working, with its original case in the photo.
Seller: virtual_dealz2
100% positive
Used$229.99delivered
$229.99 · free shipping
Buy It Now$229.99
Good buy
Titled works great, 128K. Photo shows it switched on.
Seller: enjoythetrail
100% positive
Used$309.77est. delivered
$299.99 + $9.78 shipping
Buy It Now$299.99
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Good buy
Titled bench tested, passing all diagnostics, with a case.
Seller: jessicparri_0
99.5% positive
Used$212.98est. delivered
$199.99 + $12.99 shipping
Buy It Now$199.99
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Our take
Titled with a screen issue. Price it as a repair.
Seller: lincolnpawn
99.6% positive
Used$311.67est. delivered
$299.97 + $11.70 shipping
Buy It Now$299.97
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Our take
Titled Black LCD. Photo shows the screen on and readable.
Seller: beast_tista
99.1% positive
Used$325.00delivered
$325.00 · free shipping
Buy It Now$325.00
Our take
Titled high-contrast screen, dated 1993. Photo shows a case, user's guide and AAA cells.
Seller: shopbymail
100% positive
Used$440.03est. delivered
$430.00 + $10.03 shipping
Buy It Now$430.00
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Our take
With its box, shown in the photo. No test claim.
Seller: prunehill
100% positive
Used$564.84est. delivered
$549.99 + $14.85 shipping
Buy It Now$549.99
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Our take
Surveying kit, with a Topcon FC-48GX card, 512K RAM and a case. Titled tested.
Seller: ricardo3529
99.8% positive
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