Z80CPM vs CalcBoard
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Z80CPM
Experience the classic CP/M operating system on your iOS or Mac device with a full Z80 processor emulator. Run authentic CP/M software, including operating systems, word processors, programming languages, and text adventures. Works offline with support for multiple disk images.
- Full Z80 emulation
- VT100 terminal support
- Multiple disk image mounting
- Offline functionality
- Native Mac support
- Downloadable CP/M disk images
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RomWBW CP/M brings the classic CP/M operating system to your iPhone, iPad, and Mac with a full Z80 processor emulator. FEATURES • Full Z80 Emulation - Accurate instruction emulation runs authentic CP/M software • VT100 Terminal - ANSI escape sequence support for text adventures and productivity apps • Multiple Disk Support - Mount up to 4 disk images simultaneously • Download Disk Images - Fetch CP/M disk images directly from the RomWBW project • Works Offline - Downloaded disk images are stored locally • Native Mac Support - Runs natively on macOS via Mac Catalyst CLASSIC SOFTWARE Run the software that defined personal computing: • Operating Systems: CP/M 2.2, CP/M 3, ZSDOS, NZCOM, ZPM3 • Word Processing: WordStar • Programming: Turbo Pascal, Microsoft BASIC • Text Adventures: Zork, Adventure, Hitchhiker's Guide to the Galaxy • Databases: dBASE II • And thousands more CP/M programs GETTING STARTED 1. Open Settings and download a disk image (CP/M 2.2 recommended) 2. Select the disk image for Unit 0 3. Press Play to start the emulator 4. Press 0 at the boot menu to boot from disk BUILT ON ROMWBW This emulator is built on the RomWBW HBIOS platform, the same firmware used by real retro Z80 hardware projects. Disk images are downloaded from the official RomWBW project and include freely distributable CP/M software. TECHNICAL DETAILS • 80x25 character terminal display • hd1k disk format (8MB per slice, 64MB per disk) • Hardware keyboard support • Portrait and landscape orientation Perfect for retrocomputing enthusiasts, computer history education, or anyone who wants to experience the operating system that launched the personal computer revolution.
CalcBoard
Perform multiple calculations simultaneously on one screen, compare prices side-by-side, and access various modes like scientific and programmer. This ad-free utility offers precise results and stores your data locally.
- Multiple independent calculator panels
- Side-by-side price comparison
- Scientific, programmer, and unit converter modes
- Visible expression history
- Shared value tray for chaining calculations
- Named variables for complex formulas
- Ad-free and no tracking
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CalcBoard is a calculator with no ads, no subscriptions, and no tracking. Compare prices side by side, run multiple calculations at once, and get precise results — without a single pop-up interrupting your math. NO ADS. NO SUBSCRIPTIONS. EVER. CalcBoard will never interrupt your calculations with pop-ups, banners, or full-screen ads. Premium features are available through a single one-time purchase — no monthly charges, no recurring fees. COMPARE PRICES SIDE BY SIDE Shopping for the best deal? Open two calculators on the same screen and compare unit prices, discounts, or totals without switching back and forth. CalcBoard is the fastest way to figure out which option actually saves you money. MULTIPLE CALCULATORS, ONE SCREEN Run up to eight independent calculator panels simultaneously. Compare prices, check homework, run different scenarios, or calculate tips for a split bill — all without losing your place. SEE YOUR WORK Every expression stays visible as you type — no more guessing what you entered. Every calculation is saved automatically; bookmark and label the important ones, and with Premium search your full history and export it to CSV. FOUR POWERFUL MODES • Basic — Clean, fast arithmetic for everyday math • Scientific — Trig, logs, exponents, and advanced functions • Programmer — Hex, binary, octal, and decimal shown at the same time, with bitwise operations • Unit Converter — 79 units across 10 categories: length, mass, temperature, area, speed, time, data, volume, energy, pressure SHARED VALUE TRAY Push any result to the shared value tray and pull it into another panel. Chain calculations across panels without retyping numbers. NAMED VARIABLES Type tax=0.0825 once, then use price*tax in any panel. Your variables persist between sessions and work in every calculator mode. INSTANT ACCESS FROM CONTROL CENTER (iOS) Add CalcBoard to your iPhone's Control Center and launch it in a single tap from any screen — no hunting through your home screen. Open Settings → Control Center to add the CalcBoard control. PRECISE RESULTS CalcBoard uses arbitrary-precision decimal arithmetic. No floating-point rounding errors. 0.1 + 0.2 = 0.3, exactly. YOUR DATA STAYS ON YOUR DEVICE No ad SDKs, no analytics trackers, no unnecessary permissions. Your calculations are stored locally and never leave your device. DESIGNED FOR EVERYONE • VoiceOver and TalkBack labels on every key • Light and dark themes with 8 color options and 6 button styles • Large touch targets and haptic feedback on every button • Full iPad support with Split View and hardware keyboards FREE TO START, PAY ONCE TO UNLOCK Two calculator panels and basic mode are free, forever. One purchase unlocks everything — scientific mode, programmer mode, full unit converter, extra panels, shared value tray, full history with search and export, themes, and more. No subscriptions. No recurring charges.
Screenshots
Verdict
The clearest difference is in-app purchases: Z80CPM at none against CalcBoard's 1. Z80CPM also leads on update cadence (every 10 days vs every 3 months) and device support (4 vs 2). On price, rating, ratings volume and ads there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. CalcBoard sells 1 one-off in-app purchase. Z80CPM asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 5.0 for Z80CPM against 5.0 for CalcBoard. Both are backed by a comparable volume of ratings — 2 and 1 respectively.
Z80CPM ships an update every 10 days, CalcBoard every 3 months. The most recent releases landed on October 5, 2026 and October 28, 2026 respectively.
| Parameter | Z80CPM | CalcBoard |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (2 ratings) | 5.0 (1 ratings) |
| Number of ratings | 2 — better | 1 |
| Update frequency | Every 10 days — better | Every 3 months |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod, Mac — better | iPhone, iPad |
| Requires iOS | 15.0 — better | 16.0 |
| Further details — not scored | ||
| Size | 1 MB | 50 MB |
| Age rating | 4+ | 4+ |
| Developer | Aaron Wohl | Colby Clark |
In-app purchases
Z80CPM
No in-app purchases
CalcBoard
- CalcBoard Premium$2.99









